WO2001015382A1 - Legitimacy protection of electronic document and a printed copy thereof - Google Patents

Abstract

An electronic document (200) and a corresponding printed document capable of having their legitimacy protected, and a method, an apparatus, a computer program product and a system for protecting the legitimacy of electronic and printed documents are disclosed. The electronic document (200) includes: content of an original document in electronic form, a content digest for the content the original document in electronic form, an electronic seal or e-seal (224) for authenticating the original document in electronic form, the e-seal (224) including a visible seal of an authority and the content digest embedded in the visible seal; an optically sensitive or sensible component (120C) added to the authenticated document for printing using a trusted printing process. The optically sensitive or sensible component (120C) contains information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

Description

Legitimacy Protection of Electronic Document and a Printed Copy Thereof

FIELD OF THE INVENTION The invention relates to secure electronic and printed documents and, more particularly, to a method and apparatus for providing integrated legitimacy protection of electronic and printed documents.

BACKGROUND In daily business and personal life, electronic and paper versions of a document are equally important and are important, ubiquitous items, especially in view of the proliferation of the Internet and like networks. Despite this, conventional approaches of protecting the legitimacy of one form of the document have ignored protection of the other form of the document. A number of conventional methods and systems are described below.

U.S. Patent Nos. 4,981,370 (issued to Dziewit et al. on 1 January 1991), 5,031,214 (issued to Dziewit et al. on 9 July 1991), 5,163,091 (issued to Graziano, et al on 10 November 1992), and 5,191,613 (issued to Graziano, et al on 2 March 1993) describe contract (or single signer document) signing processes, addressing the problems of electronic contract signing: security, tangibility, reliability, authentication, longevity and validity. The apparatus described in these patents produces a final authenticated document using computerized techniques. The document is stated to satisfy the legal document authentication and authenticity requirements traditionally associated with printed documents. The document authentication process is activated as part of a program that verifies the identicalness of the document at the transmitting and receiving station through a high speed comparison and locks in the document so that modifications cannot occur. The process then awaits authentication handshakes from the two end points. Once the identities of the signatories of the document are verified, the document authentication apparatus prompts the parties to authenticate the document by appending an electronic signature thereto. The actual "signing" or authenticating of the electronic document can be implemented as an additional password step utilizing a personnel identity validation apparatus. Therefore, two levels of password protection can be used such that there exists a separate "document authenticating password". The more sophisticated the system is the more assured a court can be that a document's authentication is valid. In this manner, no paper document version of the electronic contract need be produced. The traditional elements of a paper contract are all present in electronic form in the computer system.

Additional capabilities are obtained since this is a knowledge-based computer system and this can automate much of the document creation and authentication process. In particular, the creation of a multi -party document, such as a contract, entails a significant amount of interaction among the contracting parties. This is especially efficient in the arena of Electronic Document Interchange (EDI), where standard form messages are exchanged between the parties to order and invoice goods.

Thus, these four patents deal with electronic contract negotiation and signing process. However, the disclosure of these documents fails to address an integrated solution for both electronic and printed documents and on ways to make a document tangible and acceptable to people.

U.S. Patent No. 5,742,685 (issued to Berson, et. al. on 21 April 1998) describes a method for verifying an identification card and recording verification of the same. A person whom the identification card identifies is scanned to produce a digital signal associated with some text message, which is compressed, encrypted, coded as a 2-D barcode, and printed on the backside of the identification card. To validate the card, the coded message is scanned, decoded, and decrypted, expanded, and displayed. Authentication can be carried out by comparing the displayed image and text with the image and text printed on the card.

Similarly, Huttinger, Stephan, "Online Ticket" Computer Graphik, Vol. 11, pp. 9-10, Jan. 1999 describes an online ticket that is delivered to a customer, which is selected and paid via the Internet. On the ticket, a 2-D barcode is provided representing the data of the tickets and signature. A digital signature technique is used to prove the authenticity of the ticket.

U.S. Patent No. 4,853,961 (issued to Pastor on 1 August 1989) describes a system for authenticating a document, including a device having a decryption key. Upon application to information provided by a user, the system reveals not only a plain text message indicating the source of the authentication but also provides the decryption key for use with the information provided by the mailer. Similarly, US Patent No. 5,388,158 (issued to Berson on 7 February 1995) describes a secure document and a method and an apparatus for producing and authenticating the same. A document is scanned to produce a digital signal, which is compressed, encrypted, and coded as a two-dimensional barcode or like form of coding. The barcode is incorporated into a label affixed to the document. A signal representing the image is encrypted using a public key encryption system, and the key is downloaded from a center. To facilitate authentication, the corresponding decryption key is encrypted with another key and incorporated on the card. To validate the document, the coded signal is scanned from the label, decoded, decrypted, expanded and displayed. The card may then be authenticated by comparison of the displayed representation of the image and the document.

U.S. Patent No. 5,157,726 (issued to Merkle, et. al. on 20 October 1992) describes a system for authenticating a hard copy of an original document. At the sender's station, the original document and an identification (ID) card are inserted into a special copying machine. The machine digitizes the document text to produce a digital signature, which incorporates unique information from the sender's ID card. This machine produces a hard copy of the document, to which is added the digital signature. The sender retains the original, but forwards the copy to the recipient or receiver. The receiver inserts the received copy into the machine at his location, which digitizes and processes the document text and signature and indicates whether the digital signature is valid. U.S. Patent No. 5,710,886 (issued to Christensen, et. al. on 20 January 1998) describes a method for distributing, generating, and redeeming discount coupons, rebate or gift certificates. The method tracks each coupon using a consumer ID number printed on the coupon. Coupons may be distributed electronically, for example, in the form of a diskette or CD-ROM software. Software on the diskette or CD-ROM may prompt a consumer to call a 1-800 number for a validation number or code. During the phone call, telemarketing personnel request consumer demographic and or identification information, which can be entered into a centralized database. Once the software is validated, a consumer may print out selected coupons. Each coupon can be printed only a limited number of times. Each coupon can also be imprinted with a consumer ID number, preferably in the form of a bar code. The patent states that "the use of a consumer ID number on the coupon may reduce or prevent the fraudulent copying and redemption of coupons".

U.S. Patent Nos. 5,374,976 (issued to Spannenburg on 20 December 1994),

5,823,576 (issued to Lambert on 20 October 1998) and 5,018,767 (issued to Wicker on 28 May 1991) describe methods for protecting paper documents against photocopying. These methods use a high resolution printing machine (e.g., 600 dpi), to print a document with embedded patterns. These embedded patterns are not visible on the original document. After being photocopied by an ordinary photocopier, which has a lower resolution (e.g. 300 dpi) the patterns become visible.

The above techniques have a number of disadvantages. Firstly, the techniques for electronic document authentication are not user- friendly. In other words, the techniques do not make the electronic document tangible or easily comprehendable to users. An encryption key or 2-D barcode is not directly readable by users, and the users do not know whether the document or item is authorized and by whom the document is authorized. Secondly, technologies are not known to exist that provide an integrated solution for both electronic and printed document. This is critical for mission-critical applications, either for business or daily life. With an integrated solution, the benefit of high-speed delivery via the Internet and an Intranet can be enjoyed, while keeping the convenience and tangibility of a paper document. Thirdly, the protection provided by these techniques is not personalized. This is also important for legal and business document, where each person would be interested in protecting or being responsible for the content of his/her part.

U.S. Patent Nos. 5,742,685 (issued to Berson, et. al. on 21 April 1998), 4,853,961 (issued to Pastor on 1 August 1989) and 5,388,158 (issued to Berson on 7 February 1995) disclose methods or systems for protecting electronic or paper document using cryptographic technique. However, these systems have a number of disadvantages including: 1) The methods or systems only provide a solution for an electronic or paper document only; 2) The methods or systems are based on cryptographic techniques, which are secure for an electronic document, but are not tangible and convenient to users in many applications. A paper document is still preferable for many applications and preferred by many people;

3) The protection is not personalized, even true for documents with multiple signers; and

4) There is no total solution/product/service for authentication and delivery.

Thus, a need clearly exists for a method of protecting the legitimacy of both electronic and printed versions of a document overcoming, or at least ameliorating, one or more of the foregoing disadvantages.

SUMMARY OF THE INVENTION The aspects of the invention seek to provide an integrated method of protecting the legitimacy of electronic document and a corresponding printed version. This is implemented by user-friendly e-seals. The protection is personalized using a personal e-seal. Documents with multiple signers can be effectively and efficiently protected and verified.

In accordance with a first aspect of the invention, there is disclosed an electronic document for reproduction of a corresponding printed document capable of having the legitimacy of the electronic document protected, the printed document being a printed version of the electronic document, the electronic document including: content of an original document in electronic form; a content digest for the content the original document in electronic form; an electronic seal or e-seal for authenticating the original document in electronic form, the e-seal including a visible seal of an authority and the content digest embedded in the visible seal; an optically sensitive or sensible component added to the authenticated document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

In accordance with a second aspect of the invention, there is disclosed a printed document reproduced from an electronic document capable of having the legitimacy of the printed document protected, the printed document being a printed version of the electronic document, the printed document including: rendered content of an original document; an electronic seal or e-seal for authenticating the original document rendered in the printed document, the e-seal including a visible seal of an authority and a content digest for the content of the original document embedded in the visible seal; an optically sensitive or sensible component rendered in the authenticated document using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

In accordance with a third aspect of the invention, there is disclosed a method of protecting the legitimacy of an electronic document and a corresponding printed document, the printed document being a printed version of the electronic document, the method including the steps of: generating a content digest for an original document in electronic form; authenticating the original document in electronic form using an electronic seal or e-seal, the e-seal including a visible seal of an authority and the content digest embedded in the visible seal; adding an optically sensitive or sensible component to the authenticated document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

In accordance with a fourth aspect of the invention, there is disclosed an apparatus for protecting the legitimacy of an electronic document and a corresponding printed document, the printed document being a printed version of the electronic document, the apparatus including: means for generating a content digest for an original document in electronic form; means for authenticating the original document in electronic form using an electronic seal or e-seal, the e-seal including a visible seal of an authority and the content digest embedded in the visible seal; means for adding an optically sensitive or sensible component to the authenticated document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

In accordance with a fifth aspect of the invention, there is disclosed a computer program product having a computer usable medium having a computer readable program code means embodied therein for protecting the legitimacy of an electronic document and a corresponding printed document, the printed document being a printed version of the electronic document, the computer program product including: computer readable program code means for generating a content digest for an original document in electronic form; computer readable program code means for authenticating the original document in electronic form using an electronic seal or e- seal, the e-seal including a visible seal of an authority and the content digest embedded in the visible seal; computer readable program code means for adding an optically sensitive or sensible component to the authenticated document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

In accordance with a sixth aspect of the invention, there is disclosed a system utilising a network for protecting the legitimacy of an electronic document and a corresponding printed document, the printed document being a printed version of the electronic document, the system including: means for generating a content digest for an original document in electronic form; means for authenticating the original document in electronic form using an electronic seal or e-seal, the e-seal including a visible seal of an authority and the content digest embedded in the visible seal; means for adding an optically sensitive or sensible component to the authenticated document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document.

In accordance with a seventh aspect of the invention, there is disclosed a system for protecting the legitimacy of an electronic document and a corresponding printed document, the system including: means for generating an authenticated electronic document, the authenticated electronic document including content of an original document in electronic form, an electronic seal or e-seal for authenticating the original document in electronic form, the e-seal including a visible seal of an authority and a content digest embedded in the e-seal; means for generating an optically sensitive or sensible component added to the authenticated electronic document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document; means for verifying the legitimacy of the authenticated electronic document; means for printing the authenticated electronic document and the optically sensitive component using the trusted printing process dependent upon the verifying means to provide an authenticated printed document.

In accordance with a eighth aspect of the invention, there is disclosed a method for protecting the legitimacy of an electronic document and a corresponding printed document, the method including the steps of: generating an authenticated electronic document, the authenticated electronic document including content of an original document in electronic form, an electronic seal or e-seal for authenticating the original document in electronic form, the e-seal including a visible seal of an authority and a content digest embedded in the e-seal; generating an optically sensitive or sensible component added to the authenticated electronic document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document; verifying the legitimacy of the authenticated electronic document; printing the authenticated electronic document and the optically sensitive component using the trusted printing process dependent upon the verifying step to provide an authenticated printed document.

In accordance with a ninth aspect of the invention, there is disclosed a computer program product having a computer usable medium having a computer readable program code means embodied therein for protecting the legitimacy of an electronic document and a corresponding printed document, the computer program product including: computer readable program code means for generating an authenticated electronic document, the authenticated electronic document including content of an original document in electronic form, an electronic seal or e-seal for authenticating the original document in electronic form, the e-seal including a visible seal of an authority and a content digest embedded in the e-seal; computer readable program code means for generating an optically sensitive or sensible component added to the authenticated electronic document for printing using a trusted printing process, the optically sensitive or sensible component containing information for indicating copying or modification of the printed document in a copy or modified version of the printed document; computer readable program code means for verifying the legitimacy of the authenticated electronic document; computer readable program code means for printing the authenticated electronic document and the optically sensitive component using the trusted printing process dependent upon the computer readable program code means means for verifying to provide an authenticated printed document.

In accordance with a tenth aspect of the invention, there is disclosed a method of trusted document delivery via a network, the method including the steps of: establishing a secure communication link between parties at one or more locations; verifying the identity of each party; providing means for a party to sign an original document; protecting the legitimacy of a signed document in electronic form, the protected signed document including content of an original document in electronic form, a content digest for the content of the original document in electronic form, and an electronic seal or e-seal for authenticating the original document in electronic form, the e-seal including a visible seal of an authority and the content digest embedded in the visible seal; sending a protected, signed electronic document from a sending party at a first location to a receiving party at a second remote location of the network; notifying the receiving party of the sent protected electronic document; receiving the sent protected electronic document at the second remote location of the network; and sending a receipt of the sent protected electronic document to the sending party at the first location.

BRIEF DESCRIPTION OF THE DRAWINGS In the following description, embodiments of the invention are described in relation to the drawings, in which:

Figs. 1A-1C are greyscale images illustrating an example of an e-seal and the roles of the e-seal's components in file protection in accordance with the embodiments of the invention;

Fig. 2 is a block diagram illustrating a content definition scheme for documents with multiple signers in accordance with the first embodiment of the invention;

Fig. 3 is a greyscale image provided as an example of watermarking a seal image (i.e., the Lina image) using binary coding to embed the document digest in spatial domain in accordance with the embodiments of the invention;

Fig. 4 is a block diagram illustrating the layout of a document having electronic seal (e-seal) protection in accordance with a first embodiment of the invention;

Fig. 5 is a block diagram illustrating a process of electronic document authorization using an e-seal in accordance with the first embodiment of the invention; Fig. 6 is a block diagram illustrating a verification process for an electronic document in accordance with the first embodiment of the invention;

Fig. 7 is a block diagram illustrating a printing process for converting an electronic document into a printed version in accordance with the first embodiment of the invention;

Fig. 8 is a block diagram illustrating a verification process for paper document in accordance with the first embodiment of the invention; and

Fig. 9 is a diagram symbolically illustrating a service center for certification/notarisation in accordance with the embodiments of the invention.

DETAILED DESCRIPTION

An electronic document and a printed document capable of having their legitimacy protected, and a method, an apparatus, a computer program product and a system for protecting the legitimacy of electronic and printed documents are described. In the following description, numerous details are set forth including specific encryption techniques, water marking techniques, content digesting methods and the like, for example. It will be apparent to one skilled in the art, however, that the present invention may be practiced without these specific details. In other instances, well- known features are not described in detail so as not to obscure the present invention.

For ease of description, the embodiments of the invention are each described or referred to as a "system". Components of the system are described as modules. A module, and in particular the module's functionality, can be implemented in either hardware or software. In the software sense, a module is a process, program, or portion thereof, that usually performs a particular function or related functions. In the hardware sense, a module is a functional hardware unit designed for use with other components or modules. For example, a module may be implemented using discrete electronic components, or it can form a portion of an entire electronic circuit such as an Application Specific Integrated Circuit (ASIC). Numerous other possibilities exist. Those skilled in the art will appreciate that the system can also be implemented as a combination of hardware and software modules.

For convenience and ease of reference, the description includes the following sections:

1. Overview of System

2. The E-seal and E-seal Components

3. Protection and Verification Process 4. Product/Services

1. Overview of System

The embodiments of the invention provide an integrated document legitimacy protection system, including four products/services providing speedy delivery of trusted electronic and paper documents via the Internet and/or an Intranet, and certification/notarization services. The embodiments provide methods and products for legitimacy protection of an electronic and printed documents using an electronic seal, or "e-seal". The e-seal is a visual representation of a person's authentication of the document, and includes three major components: 1) a visible seal providing a visual identity of the person, which can be an image containing a logo, a real seal, a signature of the person, or a combination of them (with an e-seal people immediately know who authorized the document); 2) a watermark, embedded into the seal images to protect the integrity of the document and the watermarking information contains digest of the document content protected by cryptographic operations. Any modification of document content creates inconsistency between the content and the e-seal. To provide integrated protection for both electronic and paper documents, a novel digest derivation algorithm is utilised, which generates a similar digest for electronic and paper versions of a document; 3) an optically sensitive component is added to the printed document on the fly by a special printing method, controlled by a trusted party, to verify that the document's legitimacy before printing. The optical sensitive component protects the original printed document from possible forgeries, such as cut-and-paste and duplication by photocopying and rescanning. With the optically sensitive component, the verification can be done visually with simple or commonly available devices. These three components together form an integrated solution to protect both an electronic document and a printed copy of that electronic document against possible attacks.

The embodiments of the invention include four products/services, including trusted document delivery, electronic certification/notarization, an electronic check or negotiable instrument, and signing of an official document by multiple parties. The method, product, apparatus, computer program product system can be applied to different types of documents.

The embodiments of the invention offer three levels/types of protection. A visible seal provides low level protection to warn people that the document is authorized and protected. The watermark provides secure protection from possible unauthorized modification of the document's content. The optical sensitive component provides effective protection for the printed document with simple and off-line visual verification.

Advantageously, the embodiments are very user-friendly. People can deal with an electronic document in a way similar to an ordinary paper document. More advantageously, the embodiments provide an integrated solution for both an electronic document and a corresponding printed version. This is important because both an electronic version and a paper version of a document have their advantages, and both types of document are required in many applications. The integrated solution is, therefore, a key feature for mission critical applications.

Still further, the controlled, trusted printing method, which verifies the document's legitimacy before printing and adds the optical sensible component on the fly, bridges electronic and printed document and effectively prevents these documents from attacks such as a screen dump and cut-and-paste. 2. The E-seal and E-seal Components

Again, an electronic seal or e-seal in accordance with the embodiments of the invention includes a visible image identifying a person's authentication of a document. The e-seal represents effective and efficient protection regarding the integrity of the document. Figs. 1A-1C illustrate an example of an e-seal in accordance with the embodiments of the invention. Each e-seal preferably has three components: a visible or seal image, a watermark containing a digest of the content of a document, and an optically sensitive or sensible component.

Fig. 1 A shows an e-seal 110, which can be attached to, or incoφorated in, an electronic document (not shown). For ease of illustration, the e-seal 110 is depicted in a black- line rectangle. The e-seal 110 includes an image of a person's signature 110A (Jiankang Wu) acting as a visual identifier of the signer of the document. The visible seal 110A is kept in digital image format. Other visible images 110A besides a person's signature may be practised without departing from the scope and spirit of the invention. For example, the visible image 110A may be a document header, a logo, an image of a person's face, a graphical symbol, and the like. Numerous possibilities exist which will be apparent to those skilled in the art in view of the disclosure herein. Still further, the visible image 110A is preferably watermarked with information about the owner of the visible seal 110A to protect the ownership of the visible seal 110A. The e-seal 110 also includes a watermark HOB appearing as a noise-like strip under the image of the signature 110 A. The watermark HOB conveys the digest of the document's content (i.e., the information contained in the document including text, images, and the like) to protect the integrity of the document. The digest of content is described in greater detail hereinafter.

Fig. IB illustrates a corresponding e-seal 120 rendered on a printed document (not shown) and again depicted within a black-line rectangular box. The e-seal 120 includes a visible seal 120 A and a watermark 120B containing the digest of the document's content. A grey, rectangular optical sensitive or sensitive component

120C is added right under the watermark strip in the printed document when rendered. This is done prior to rendering of the drawing using a trusted rendering process. Optionally, a serial number (i.e., 99072002) is added in the component area 120C to identify the printed document. The optically sensitive or sensible component 120 contains information for indicating copying or modification of the printed document in a copy or modified version of the printed document. Fig. IC is a depiction of an e- seal 130 in a photocopy of the original printed document containing the e-seal 120 of Fig. IB. In Fig. IC, the photocopied e-seal 120 has changed appearance so that an imperceptible portion of the optically sensitive component 120 is now perceptible (i.e., the signature of Jiankang Wu) in the photocopied e-seal 130.

2.1 Visible E-seal

In the embodiments of the invention, a visible seal can be viewed as a user- friendly interface and a visual identity of an authority. Huttinger, Stephan, "Online Ticket", Computer Graphik, Vol. 11, pp 9-10, January 1999 discloses a two-dimensional (2-D) bar code for authorization of document, which is an easily detectable code of encrypted information. A bar code is a printed binary code, which can be detected by a bar code reader with a very low error rate, but is not readable by a human being. That is, with a bar code on a document, who the document is authorised by is not known, and a user cannot determine if the bar code is a valid one or not without a testing device.

An authority, either an organisation or individual, often has a unique "seal", which can be a logo, a signature, or the like. The image of the foregoing is the visible seal component of the e-seal. To protect the ownership of the e-seal, an invisible watermark is preferably embedded into the seal image. The invisible watermark information may include, but is not limited to, the name of the owner and the date of generation of the seal. Other information may be included in the seal image. If the watermarking process is not invertible, another person cannot pretend to be the owner. Image watermarking for copyright protection is discussed in Cox, Ingemar J., and Miller, Matt L., "A Review of Watermarking and the Importance of Perceptual Modeling", Proc. Of Electronic Imaging '97, February 1997.

A seal image can be locked by the owner using, for example encryption, and stored in a secure place. The owner unlocks the seal image and uses the seal image to sign a document. Access to and unlocking the seal image can be done using a password, a smart card, or biometrics.

2.2 Watermarking a Digest of Content Seals and signatures on a paper document can provide evidence of the legitimacy of the document, because the originality of the seal and the signature on the paper can be verified simply by visual inspection. For an electronic document, protection of the content of the document from unauthorised or illegal changes is mainly realized by a watermark, which is embedded into the e-seal image(s). The watermark information contains a "digest" of the document content. There are two major types of applications requiring document legitimacy protection: The first type of applications are those where documents are issued by trusted authorities. Examples include government gazettes and tickets, where the authorities or their agencies carry out the legitimacy verification. In terms of information security, the authority / key-issuer and verifier share security keys.

The second type of applications are those where documents are transferred among multiple parties. Examples include electronic legal document, and official documents in government or large companies. There may be multiple persons initiating the document and a need exists for a trusted third party issuing keys.

The word "key" includes a piece or set of information, with which a message or device can be transferred from one state to another by a specific function. For example, a security key can be used to encrypt a message. Alternatively, a set of eigenfaces being a face image mapped into a small dimension feature vector can be used. Still further, watermark information can be embedded into an image with a secret address. In the above three examples, a security key, eigenfaces and an embedding address can be all referred to as "keys" and are merely illustrative. Numerous other possible key exist and will be appreciated by those skilled in the art.

2.2.1 Content of a Document The embodiments of the invention seek to protect document content from possible tampering and/or unauthorised use. Therefore, defining the document content in the protection process is of significant importance, especially for those documents signed by multiple persons.

Basically, the content of the document refers to all information contained in the document at the time of signing (i.e. applying an e-seal to the document), including layout and format. For a document with multiple signers, the content is defined as content with respect to a particular signer. A first example is where the contract is signed by two parties. In a first round, both parties sign a plain document, being one of two copies of a contract. The contract content is the content of the document. In a second round, each party signs the other document that is already signed by the other party. In this case, the content of the document includes the signature the other party. Fig. 2 shows a second example illustrating the idea of content definition with respect to a particular signer of the document using a three signer example. A document 200 containing initial content 222 is initiated and signed by a first person, and sent to a second person. The second person signs the document and sends it to a third person. For the first person, the content 222 of the document 200 seen is the whole information contained in the original document, shown as box 222. When the second person signs the document 200, the document content 220 with respect to that person should include the content 222 of the original document 200, the first person's signature 224 and the second person's addition 226 (such as comments) to the document. To the third person, the content 230 of the document 200 includes the original document 222, the signatures of the first person (224) and second person, addition to the document by the second person 226 and the third person 236. Note that, the signature of the person is implemented as e-seal. This can be formally written as:

^c- = Σ .(^-. +^ ) + C₀ where C„ is the content of the document at the time of signing by the n ^th person, S,.ι is the signature of the previous signer, the first signing person has a sequence number of 0, and δ_l is the addition to the document by i^th signing person.

In the embodiments of the invention, the digest of the document content is embedded into the e-seal of the person when the document is signed by that person.

There is redundancy if the digest of the document content includes the original document again when the next person signs the document. The redundancy occurs because the digest of the original document content exists in all e-seals of all signing persons.

For reasons of consistency, when a person signs a document, the person verifies the legitimacy of that document against all existing signatures from the first to the last. An alternative method is to just embed the digest of the last e-seal and the person's addition to the document when a person signs the document. That is, the content of the first signer is C₀ , the content of the subsequent signers i are: S_t__x + δ_l . This is secure and simpler for the following reasons:

1) The last e-seal carries the digest of the content of the document at the time of signing and, therefore, all e-seals form a protection chain. Breaking any part of the chain results in unsuccessful authentication.

2) The digest of content for the i^th signer can be written as:

D_l = d(s_l_, +δ_l) = d(s r +d(s_l_₂ +δ_l__i)+δ_l) =..., where the e-seal includes two parts. One part is the e-seal image, and the other part is the digest of the content with respect to that e-seal, which is coded in the form of a watermark. The formula can be re-written until the first signer, and then the digest of the content is known with respect to the i^th signer containing "signatures" of all content of the document at the time of that person's signing.

3) Since the digest with respect to each e-seal is different, there is no confusion of on the order of signing of the document. On the other hand, people tend to place an e- seal at a location that is near that person's addition to the document. This is another cue of the signing order.

2.2.2 "Digest" of the Document The embodiments of this invention work for both electronic and printed paper versions of a document. The "digest" of the document content is able to be readily derived from both the electronic and paper versions of the document, and the derived digests are the same or quite similar. The "digest" of a document's content can be defined as a condensed representation of the document having a size sufficiently small so the digest can be embedded into the e-seal image. There are two important desired properties for the digest generation function. Firstly, the digest must be sensitive to content changes, including changes that may be quite small. Secondly, desirably the digest is sensitive to spatial locations so that the location of changes can be detected as well. There are many applicable methods to derive digest from documents either in electronic and in paper format. The digest can be formally represented as "Digest = M (Content)", or "Digest = M(Key, Content)", where M stands for a mapping function and "Key" is a secret value shared between the issuer and the verifier. Given below are a few examples of digesting techniques, however, it will be apparent to those in the art in view of this disclosure that other methods may be practised without deporting from the scope and spirit of the invention. The examples include:

1) In cryptography, a message digest can be generated using a secure hash algorithm. For a digest 128-bits long, approximately 2^12S messages must be tried before finding two that have the same digest C. Kaufman, R. Perlman and M. Speciner,

Network Security. Private Communication in a Public World. PTR Prentice Hall, Englewood Criffs, New Jersey, 1995, describe details of such secure hashing algorithms. Consequently, it is impractical to find two messages having the same digest. Clearly, a cryptographic digest is suitable to electronic multimedia document, where the document I_s content is digital and has a crisp definition for

"same" and "different". A cryptographic digest is also applicable to a document with text content where optical character recognition (OCR) works well to convert a paper document to electronic form. To generate a "location-dependent" digest, the text can be divided into several blocks, and a small size digest is generated for each block. The final digest integrates all of the small size digests.

A secure hashing algorithm is a pseudo-random mapping function. A single bit error in the content may result in a large difference between the digests. Therefore, the content of the document must be error- free during transmission, storage, and format conversion.

2) A simple digest of a document (e.g. degree certificate) can be derived by selection of a few key document items including the recipient, the name of the school, the name of the degree, and the date. Also, a simple way to verify both electronic and paper certificates is to manually input those items.

3) The content of a picture has a different form when compared with text. The representation of the text is exact. A one bit change in the content of text results in differences of the text and, possibly, changes of meaning as well. On the other hand, the interpretation of picture is not precise. For example, the content of a facial image may not change even if the image data is reduced from 8 bits per pixel to 4 bits per pixel. Therefore, a "feature measure" can be used to represent the content of a picture. Feature measures are extracted from a picture to capture the most salient features of the image. A typical example of feature measures for facial images is the eigenface. A. Pentland, "Eigenface for recognition", Journal of Cognitive Neuroscience, Vol. 3, pp 59-70, 1991 provides detailed information on this topic. Other examples include Fourier descriptors, projections, and vector quartisation (VQ) representation. R. C. Gonzalez and R. E. Woods, Digital Image Processing. Addison- Wesley Publishing Company, Reading, 1993 describe such methods. Since feature measures capture the salient features of a picture, a print- and-scan process does not result in much change to the measure. Therefore, detection of changes can be made between an electronic document and the corresponding printed version using a pre-determined threshold. Feature measures can be used as a digest for the picture both in electronic and paper form, as well as for other non-picture data in raster format. The eigenface and VQ each can be considered as a keyed mapping function, where eigenfaces and the VQ dictionary are keys for the mapping. Eigenfaces and a VQ dictionary vary from application to application, and there are many choices.

4) The feature measure concept can be extended to derive a digest for a non-raster data format (e.g. a symbolic representation for graphics and category or dictionary-base representation for text and table). For example, assume that a doctor did a medical check for a person. Since there are typical cases/categories and standard descriptions, those categories can be coded, the and use code number can be used to create a digest for the medical check up document.

2.2.3 A Digest Derivation Method Based on a Block- Wise Coding Technique In the embodiments of the invention, an effective digest derivation method is proposed for use based on image block- wise coding techniques J. K. Wu and R. E. Burge, "Adaptive Bit Allocation for Image Compression", Computer Graphics and Image Processing, Vol. 19, 1982, pp 392-400 describe this method in detail. The advantages of using this are that the method works for both electronic and paper documents and the method can detect both the amount of change and the location of changes.

Assume that a document is in raster format. That is, the electronic document is converted to raster data format, a paper document is to be scanned in as raster data format, and multiple pages of the document are concatenated as one raster image. The method includes the following steps:

• Step 1: An appropriate block size is chosen. Principally, the block can be of any shape and size. However, usually a block is chosen to have a square shape. The size of the square can be of 4X4, 8X8, 16X16, or 32X32 pixels, depending on the image size of the document, the digest size of the e-seal to be embedded, and the required protection accuracy. • Step 2: Each block is classified into one of a number of predetermined classes. The classification can be done in either the spatial or transform domain using either original block data or measures extracted from the block. For example, if vector quantization method is adopted, the block must be matched against a pre- determined codebook. This can be also viewed as classification. For the case of a transform domain method, first, the blocks are transformed into the Cosine transform domain. Texture energy, directionality, fineness and dispersion measures can be derived for each block. Using these four measures, the block is classified into one of, say, 16 classes (16 is merely illustrations and both larger and smaller numbers of classes can be practised). For example if the block data in Cosine transform domain is represented as F(u,v),or,F(r,θ), the four measures are defined as follows:

• Step 3: The digest of the document is determined or formed to be an anay of class labels.

Energy = ∑∑| F(u,v) \, where, F (0,0) = 0

Direction = ^^tan^_1(w / ) | F{u,v) \ I Energy

Fineness =

Dispersion = - ^*'² P_r (θ) log P_r (θ)dθ, where, P_r (θ) = | F(r, θ)dr I Energy

Step 4: For a document to be verified, a document image is processed the same way, using the same class parameters (or code book) as in step 2 to derive the digest. The derived digest is matched against the embedded digest. Class label changes of blocks indicate that modifications have occurred in those blocks.

Class definition (or codebook determination) is an important aspect of this method and can be defined for each individual document, or for a group of documents. If blocks are classified in the spatial domain, the class definition is similar to defining a code book in vector quantization. As an example, consider a class definition in the Cosine transform domain as follows: • Step 1: Choose an appropriate block size. Collect document images that can represent the group of document the classes definition apply to.

• Step 2: For all document images, transform each block into Cosine transform domain and extract measures to represent characteristics of those blocks. • Step 3: Decide the number of classes n_cls, according to the tolerance of modifications of the application: the more classes, the smaller are the modifications that can tolerated.

• Step 4: Use a clustering algorithm (e.g. K-Mean) to cluster all blocks into n_cls clusters. • Step 5: The class definition for the given document image data set is made up of cluster centers and cluster labels.

2.2.4 Authenticity Protection of the Digest and Key Management

As mentioned above, the digest of a document content is embedded into the e-seal in the form of a watermark. The watermark is used to verify the authenticity of the document content. For this puφose, the authenticity of the digest is protected through cryptographic means before the digest is embedded into the watermark. Cryptographic concepts and terminology are described Afred J. Menezes, Paul C. van Oorschot and Scott A. Vanstone, Handbook of Applied Cryptography. CRC Press, 1996.

Three techniques A), B), and C) are set forth hereinafter:

A) Authenticity protection of the digest using symmetric key encryption can be used. s is a secret key shared between the issuer and the verifier. Also, E(s, Digest) denotes the encryption of a Digest under the key s, and D(s, Ciphertext) is decryption of Ciphertext under the key _>.

The operations performed by the issuer include: i) Compute the digest from the document content: Digest = M(Content); ii) Encrypt the digest under the secret key: Ciphertext = E(s, Digest); and iii) Embed the Ciphertext into the watermark. The operations performed by the verifier include: i) Extract the ciphertext from the watermark and denote the extracted ciphertect as Ciphertext'; ii) Decrypt the extracted ciphertext under the shared secret key: Digest ' = D(s, Ciphertext'); iii) Compute the digest, Digest", from the document content, Content":

Digest" = M(Content"); iv) Compare the Digest ' with Digest ". and if the "distance" between Digest ' and Digest" is within a pre-defined threshold, accept the document as authentic; otherwise reject the document.

B) Authenticity protection of the digest of a document content can be provided using Message Authentication Check (MAC). Let s be a secret key shared between the issuer and the verifier. The MAC of the digest of a document is defined as MAC = H(s, Digest), where H() is a one-way hash function.

The operations performed by the issuer include: i) Compute the digest of the document content: Digest = M(Content); ii) Compute MAC of the digest: MAC = H(s, Digest); and iii) Embed MAC into the watermark.

The operations performed by the verifier include: i) Extract the MAC from the watermark and denote it as MAC; ii) Compute digest from the document content: Digest" = M(Content"); iii) Compute MAC" = H(s, Digest"); and iv) Compare MAC with MAC" and, if the two are equal, accept document as authentic; otherwise reject the document.

C) Authenticity protection of the digest can be provided using a digital signature, s and/? are the private and public key pair of an issuer for a given digital signature scheme. The digital signature of the issuer on the digest of a document can be denoted as SIG = S(s, Digest). There are two types of digital signature schemes — digital signature schemes with an appendix and digital signature schemes with message recovery. Without loss of generality, the latter type of digital signature schemes is assumed in the description below. Examples of such schemes are RSA, Rabin, and Nyberg-Rueppel. Generalization to the former type of digital signature schemes is straightforward for those skilled in the art. Further, the verifier is assumed to obtain the public key of the issuer in an authentic manner.

The operations performed by the issuer include: i) Compute the digest from the document content: Digest = M(Content); ii) Compute digital signature of the digest: SIG = S(s, Digest); iii) Embed SIG into the watermark.

The operations performed by the verifier include: i) Extract the digital signature from the watermark and denote it as SIG'; ii) Recover the digest from SIG' using issuer's public key: Digest' = R(p,

SIG'), where R() is the message recovery function of the digital signature scheme; iii) Compute digest from the document content: Digest" = M(Contenf'); iv) Compare Digest' with Digest" and if the "distance" between Digest' and Digest" is within a pre-defined threshold, accept document as authentic; otherwise, reject the document.

Note that approaches A) and B) are suitable for situations where the issuer and the verifier trust each other, while approach C) can be used in situations where the issuer and the verifier do not trust each other.

Keys used in watermark embedding (e.g. address and parameters) and in digest derivation (eigenfaces ...) are generated by the authorities and stored in the file of the document.

2.2.5 Watermark Embedding Unlike circumstances involving copyright protection, people do not ordinarily try to remove watermarks from an e-seal, since such people need to provide evidence establishing the originality of the document. Thus, non-perceptibility and robustness are not a major issue. Therefore, a spatial domain embedding method may be more preferable than a spectrum domain technique. The spatial domain method is simple and has a large capacity.

There are many possible watermarking techniques applicable to document content digest embedding in accordance with the embodiments of the invention. M. D. Swanson, M. Kobayashi, and A. H. Tewfik, "Multimedia Data Eembedding and

Watermarking Technologies", Proc. of teh IEEE, Vol.86, No.6, June/1998, pp. 1064- 1087 provide a review of watermark technologies.

The required properties for watermark embedding methods for document authentication are :

1) A large capacity to store document digests, the size of which varies from application to application, and.

2) Robust to print-rescan processes, which is a necessary step for verification of the paper version.

The embodiments of the invention can utilise, but are not limited to, a simple technique shown in Fig. 3. The digest 300B is embedded in a region of the e-seal image 300 A. Part of the boundary of the watermark region 300B is the boundary of the original image content 300. The boundary 300B is recorded in the document file so as to facilitate watermark extraction in the verification process. This boundary is "content-dependent" and closely couples the watermark 300B and the seal image 300A. Principally, the watermark region 300B can be of any shape and at any location, depending on the needs of the application, as long as the watermark region does not affect the perception of the major image content 300 A.

In this method, the digest 300B is coded as binary modulation of S component in HSV color space in Fig. 3. Other possible modulations to other components or in other color space are also valid. To reduce the error rate, either an error correction code can be used or the digest can be encoded with more pixels. When extracting the watermark 300B from a re-scanned document, there is no problem in recovering the information if the resolution of the scanner is high enough.

2.3 Optical Sensible Component

The visible e-seal provides an immediate warning to people regarding document legitimacy protection. Together with a visible seal, the optical sensible component provides secure protection for a printed document and easy verification by means of standard optical devices, such as a special lens or a commonly available device including a photocopier.

Any of a large number of optically sensible components can be applied in the embodiments of the invention. Preferably, either of two methods for embedding optical sensible component into a document can be used:

1) Directly embed certain secure elements into the content of the document. By detecting some "holes" in the frequency-domain, the secure elements can be embedded into these holes and later detected by an optical lens specially designed to match this particular class of document. 2) The visual elements of the document can be modulated to make the document sensitive to a particular lighting scan along a pre-defined direction by either increasing the resolution or changing the color of the document. In this case, the detector can be a commercially available photocopier or scanner.

2.4 Document Structures

Fig. 4 depicts the layout of a one page document400, including a content region 420 and two e-seal parts: a logo 410 and signature 430 (and preferably a serial number). The content region 420 can be further subdivided into several regions, each of which may contain different media, such as text, graphics, a table and/or a picture.

2.4.1 Landmarks or Frames for Easy Location Frames 410, 420, 430 can be added as landmarks for the easy location of content 420 and e-seal regions 410, 430. Other forms of a landmark can be used instead of frames without departing from the scope and spirit of the invention.

2.4.2 Multiple Parts of E-seal

There may be multiple parts of an e-seal. A typical example is a formal document 430, which includes two parts: a formal document header 410, and a signature and/or a seal 430 of an organization. The document header 410 may contain the name and logo of the organization. Classification and serial number of the document are usually printed in a place near the header as well. However, this can be part of the content 420 preferably. The visible information is embedded as watermark into the logo image 410 for protection. Commonly, a paper document to be a valid document must contain both a header and one or more signatures. Clearly, it is desirable that all images in the e-seal are watermarked to protect the ownership, although this need not be the case.

2.4.3 Multiple Pages

For a multiple page document, an e-seal can be inserted to every page. Preferably a page number (numbered as current number - total number) is included in the document and considered as to be part of document content.

2.4.4 File of Authorized Document

For each authorized document, a file containing necessary information is created and stored for further reference. The information contained in the file includes a key for authenticity protection of the digest and/or embedding, the size of the e-seal, parameters for an optically sensible component, the names of the signing persons, and the like. The file is stored with an authority or a trusted third party. A verification process can access the file.

3. Protection and Verification Process

3.1 Electronic Document Signing Process Fig. 5 illustrates the protection process for an electronic document according to a first embodiment of the invention. When a person starts the document signing process, the person needs to unlock the person's e-seal 534 using either a password or biometrics (fmgeφrint, face, etc). For a given electronic document with single signing person, verification module 510 for the verification of a previous e-seal is not applied to the electronic document or e-document 510 and the digest of the document content is generated by digest generation module 520, either with a key or without a key. A key is obtained to encrypt the digest if necessary. Address and parameters are chosen as a key 532 provided to the watermark embedding module 530 to embed the digest (as well as the time when the watermark is embedded) as a watermark into the e-seal image 534 and provide authentication of E-document file 542. Landmarks for easy location of e-seal and content can be added. The final module 540 of the process includes or adds information including the e-seal to the electronic document 512 and adds landmarks for verification and printing to provide an authenticated E-document 542 and an E-document file 544.

In case of multiple signing persons, at the time of the n^th signing person, verification is conducted using module 510 to validate all previous e-seals. The person's additional information is added to the document, a digest derived with respect to that person, and the digest encrypted and embedded. Information relating to the signing (adding the e-seal of that person) is added to the file of the electronic document.

For many applications, the content of the document includes main content, classification number, serial number, page number and all other information contained in the document.

For applications requiring high security, personal authentication of the signing person is necessary. This can be done using a password, a biometrics such as fingeφrint and face, or smartcard. After successful personal authentication, the system does the following: unlocks the e-seal image, signs the document, and charges the cost to the person's account. 3.2 Verification Process for Electronic Document

Fig. 6 illustrates the verification process for an authenticated electronic document 542 containing an e-seal and the corresponding electronic file 544 as input. First, the e- seals are located and verified by module 610. With information from the file, the watermark of each e-seal is extracted and decrypted to get the original digest. The digest of the content with respect to each e-seal is extracted from the electronic document, and compared with the digest extracted from the e-seal by module 620. The verification is successful if there is no difference or the difference is under a predefined threshold. In certain cases, validation of the e-seal image may be required to check the true ownership (of the e-seal) by extracting the copyright protection watermark in module 630 to produce verification result 644. If the verification result 644 is "Yes" or "true", this indicates that the authenticated electronic document is an original. If the verification result 644 is "No" or "false", this indicates that the document is not an original or is a forgery and the forgery is likely located at location (x,y).

3.3 Printing of Electronic Document

Printing of an electronic document 542 to get an authenticated printed copy 734 is controlled by the printing method shown in Fig. 7. The legitimacy of the electronic document is verified by verification module 710. If the verification is successful, an optical sensible component is added (preferably with a copy number) by adding module 720. The document is then printed by module 730. A serial number of the printed copy can be added to the document file, as well to the printed copy. The optical sensitive component is added to the e-seal of the last signer, which provides overall protection of the document including previously signed e-seals.

A valid printed document can be only generated by the printing method of Fig. 7. This ensures that people cannot edit and then print the electronic document using any printing functions. By controlling the usage of the printing function, the legitimacy of the printed document can be secured to a large extent using the optically sensible component. There are several ways to control the printing function. In this embodiment of Fig. 7, since there must be verification before printing, the printing function is controlled by parties who have verification rights and the verification is well facilitated. Following are two ways of controlling the printing function.

1) On-line control: A user logins on through a secure network and requests printing of a particular electronic document. After successful user verification by the authority or the trusted third party, the authority or trusted third party verifies the document and sends the printing function together with necessary data over to the user's site. The printing function prints the document on the user's printer. The document being printed, the portion of the data that has been printed already can be destroyed as the printing process is in progress. This can be done by erasing the memory containing that data portion progressively.

2) Verification and printing agent: An authorized agent may have a special printing device. The printing device can be either on-line connected to the authority or off-line. In the off line case, data and functions are preloaded into the device. The device prints out the document when a user is authorized. When the device runs in an on-line mode, the process is similar to the first approach. Partial data and function can be stored with the device depending upon the degree of security the device has.

3.4 Verification Process for Printed Document There are three levels of verification for a printed document. As shown in Fig. 8, the verification starts with a printed document 734 to be verified, together with certain information about the document contained in a file of the document 544. The difference in verification of the electronic and paper document 644, 734 is that the paper document 734 can be verified by visual inspection, and the paper document 734 has to be scanned to convert it to digital form before the paper document can be verified the same way as electronic document 544. The first level of verification is the visual inspection of the e-seals by module 810, the second level verification is the verification of the optically sensible component by module 820. The verification device again can be a simple optical device, such as a special lens or an ordinary photocopier. After photocopying, certain patterns should become visible/invisible on the optical sensible component. This pattern is invisible/visible within usual viewing distance on the original printed copy 734. The verification process can stop at module 810 or 820 if the verification result is "OK" and the level of verification is acceptable.

The third level verification is to scan the paper document to convert it back to a digital form using a scanning module 830. However, the digital document obtained by scanning is in its raster data format, which is different from the original electronic document where text, graphics and tables are coded in their usual way. Noise and other distortion may be added to the e-seal images and picture content although they are originally in raster format. Therefore, the watermark extraction module 840, and the digest extraction module 850 should tolerate distortion and format differences. If an application chooses to use selected items as digest of the content, manual inputting of the selected items may work well for both electronic and printed documents 544, 734.

After watermark extraction 840 with the keys, the original digest of the content is recorded and compared with the digest extracted from the content of the paper document by module 850. The verification is successful if there is no difference or the difference does not exceed a threshold providing a positive verification result 854. [PLEASE CONFIRM IF OBJECT 854 SHOULD BE LABELLED "VERIFICATION RESULT.]

4. Product/Services

There are many possible products and services that can be created from the embodiments of the invention. Listed below are two examples. The basic concepts are applicable to numerous other similar applications.

4.1 Delivery of Trusted Copy Currently, official letters and many other secure documents are delivered physically, via postal services or express deliveries such as Federal Express. The embodiments of the invention facilitate the electronic delivery of a trusted copy of a document. That is, a recipient can receive a trusted document either in electronic and/or in paper form. There are two types of settings described below.

The first setting involves the sender's organization being an authorized identity and having set up a computer system, with the functionality described above:

1) The sender prepares an electronic document by either editing an electronic document or scanning in a paper document. The sender then logs into to the organization's computer system, gets authorized, unlocks the person's e-seal, signs the document, and sends the document to the recipient while specifying if the server wants the recipient to receive the document in electronic and/or paper format. 2) When the recipient receives a notification (organization-organization or organization-individual) or when the recipient requests a document (tickets, coupon, gazettes, receipts...), the recipient logs into the sender's system, gets the electronic document, and/or prints out the paper document. When the document is printed, the printing function from the sender's system is invoked, and the sender's e-seals and optical sensitive component are added to print a trusted copy.

The second settings involves a document being sent through a service center: 1) The sender prepares an electronic document by either editing an electronic document or scanning in a paper document. The sender logs into a service center, gets identified, unlocks the person's e-seal, signs the document, and sends the document to the recipient while specifying if the sender wants the recipient to receive the document in electronic and/or paper format. 2) When the recipient receives a notification (organization-organization or organization-individual) or when the recipient requests a document (tickets, coupon, gazettes,...), the recipient logs into the service center, gets the electronic document, and/or prints out the paper document. When the document is printed, the printing function from the service center is invoked, and the sender's e-seals and optical sensitive component are added to print a trusted copy. Alternatively, the service center can add a notarization seal and optical sensitive component to certify the true copy.

4.2 Certification and Notarization

Currently, certification and notarization for official documents and papers such as graduate certificates, marriage certificates, and transcripts are all done in paper form. For example, a university student in Asia applying for graduate admission to a US university has to get all of that person's certificates and transcripts initiated by the university authority and sent through the public mailing system. A significant problem is that there are many universities in the world. Further, it is difficult for an admission official to judge the legitimacy of those documents. Still further, the student does not know if the documents the student sent are acceptable.

The product of certification and notarization here applies to all types of documents, including, but not limited to, birth certificates, maniage certificates, degree certificates, and official letters. Degree certificates are used as an example in the following description. The embodiment of the invention is directed to the framework and technologies for operation of a certification/notarization service center.

The service center 910 shown in Fig. 9 provides on-line services to document issuers 930 (e.g. the university the student obtained the degree from), document owners 920 (graduates), and document recipient 940 (the university the student is applying for a higher degree admission). Processes for various requests are as follows:

Firstly, an owner 920 requests an electronic degree certificate through the service center 910 with the indicated issuer 930 and the following steps are performed: 1) An owner 920 logons to the webpage of the service center 910, gets registered if not yet already done, and fills in a request form. 2) The service center 910 communicates with the issuer 930 about the request and arranges business links between the service center 910 and the issuer 930 if not yet already done.

3) The issuer 930 connects to the service center 910, issues an electronic degree certificate for that owner 920, and sends the certificate to the owner 910 through the service center 910.

4) The service center 910 keeps a record of the certificate, which is collected during the issuing process and is enough for the verification service. 5) The owner 920 can choose to either keep the e-certificate, or rent a secure deposit box to keep the certificates in the service center 910.

Secondly, an alternative way is that the owner 920 brings in a paper document (degree certificate) to the service center 910 and requests an electronic certificate service, which includes the following steps:

1) The service center 910 verifies the legitimacy of the paper document with the original issuer 930 on its capacity, converts the paper document to electronic form, signs on the electronic version and assigns a trust level to the document. For example, the trust level can be high if verified with the original issuer.

2) The service center 910 keeps a record of the certificate.

3) The owner 920 can choose to either keep the e-certificate, or rent a deposit box to keep certificates in the service center 910.

Thirdly, an owner (student) 920 requests to send an electronic document (degree certificate) to a recipient 940 (the university the student is applying for a higher degree study) and includes the following steps.

1) The owner 920 logs into the webpage of the service center 910 and fills in a request form. 2) The service center 910 verifies the electronic document and sends the document to the recipient 940 together with service center's e-seal and security statement (level of trust). 3) The service center 910 notifies the owner 920 of the status when the recipient 940 has collected the electronic document.

Fourthly, a party can request the service of document legitimacy verification including the following steps:

1 ) The party should register with the service.

2) The registered party logs on to the webpage of the service center 910, and sends in the electronic document.

3) The service center 910 checks for the record of the document and carries out the verification. If there is no record, the service center 910 contacts the issuer 930 for verification, and then puts the service center's e-seal into the document together with a security statement.

4) The service center 910 keeps a record of that document and sends back the electronic document to the registered party.

Fifthly, the service center 910 receives a request to print a hard copy of an electronic document either from an owner 910 or another party.

1) The user should registers with the service center 910.

2) The user logs into the webpage of the service center 910 and sends in the electronic document.

3) The service center 910 performs verification on the electronic document, assigns a trust level to the document, and prints a copy together with the center's e-seal and a dedicated optical sensitive component.

Sixthly, the service center 910 receives a request for legitimacy verification of a printed copy involving the following steps:

1) The service center 910 verifies the validity of the e-seals by visual inspection.

2) The service center 910 verifies the validity of the optically sensitive component. 3) The service center 910 scans in the paper document, and verifies the document legitimacy by checking the document content digest and ownership of the e-seal (if necessary).

In the sixth process, the service center 910 need only keep a record of the document that is necessary for verification services. The record is created and the data is collected when the document is signed using the services provided by the service center 910. That is, the service center 910 does not keep a copy of the whole document. By doing so, the authority of the issuer 920 is well respected, and the privacy of the owner is protected. When a user chooses to rent a deposit box in the service center 910, the deposit box is protected by the user. The service center 910 does not have any right to access the content of the deposit box.

The owner 920 of the certificates can choose to send the e-certificates to anyone directly.

The service center 910 is advantageous for a number of reasons:

1) There are many document issuers in the world, and there is little or no information available about issuers and those issued documents. Consequently, there is hardly any effective means for legitimacy verification.

2) It is time consuming and costly for owners to send paper documents and also to provide official evidence regarding the legitimacy of the documents. 3) It is not efficient for each issuer to provide a verification service regarding the legitimacy of certificates and other documents.

4.3 Electronic Check

Checks or negotiable instruments are used and prefened by many people to pay their bills. The parties involved are a payer, a payee, a payer's bank, a payee's bank and the service center. An electronic check services product is as follows: Firstly, the payer issues a check involving the following steps:

A) The payer registers with the service center 910 for the service.

B) The payer logs on to the service center 910 through the center's webpage. C) The payer fills in the form for payment and signs the form using the same means as with the bank (pin, fingeφrint, face, or others). The form includes information about the payer's bank and bank account, the person's name and identification number, the payee's name, amount, and the date of the payment. D) The service center 910 links to the payer's bank for validation.

E) The service center 910 signs the check with both the payer's and service center's e-seals and sends the check to the payee.

F) After the payee picks up the check, the service center 910 notifies the payer. G) The payer can choose to print out the check using the printing function provided by the service center 910, and personally give the check to the payee. The printed check has security feature of the payer's bank, the signature of the payer, the seal and optical sensitive component from the service center 910 and is trusted. Secondly, the payee claims the check involving the following steps:

A) The payee registers with the service center 910.

B) The payee logs on to the service center's webpage.

C) The payee sends in the electronic check to the service center 910.

D) Alternatively, the payee can send the check to payee's bank, and the bank scans in to read any required information from the check, and sends the information to the service center 910.

E) The service center 910 verifies the check with the original form filled in by the payer.

F) The service center 910 sends the check to the payee's bank with verification result.

G) The payer's bank accepts the check and commits the transfer on the due date indicated in the check. H) In case of check refusal by the payer's bank, the payer's bank signs on the check for refusal. The service center 910 notifies the payer, payee, and payee's bank together with a copy of the check singed for refusal. I) For all cases, if a printed copy is requested by the payer, the payer's bank, the payee and the payee's bank, the service center verifies the check with the original form, adds an optical sensitive component that designed for that check, and prints a paper copy.

4.4 Service Center for Secure Document with Multiple Signers For the multiple signers of the document, it is assumed that all the signers have registered with the service center 910 or the system administrator of the organization, that the service center 910 has obtained a public key certificate for the business, and that the users (signers, recipients,...) have obtained their own public key certificates.

For the case of a contract between several parties, this involves the following steps:

A) The parties communicate to get the final copy that is agreeable to all the parties. The service center 910 puts a seal to freeze the document and sends the document to one of the signer to start signing.

B) All the parties log on to the service center 910 ready for signing. C) One of the parties signs the document and sends the document to the next party and so on until all the parties have signed the document. The signing process automatically verifies the validity of the service center's seal to make sure there is no change to the agreed version. The record of the document is created at the service center 910 during signing process. D) Alternatively, all the parties sign the document simultaneously. That is, after first signing, the signers send the document back to the service center 910, the service center 910 distributes the document to parties for the second signing, and so on. In this case, the number of copies of the signed document is the same as the number of signers. Each copy has a different order of signings, but the same effectiveness.

E) The signed copies are kept with signers. The signers can choose to rent deposit boxes from the service center 910 to keep their copies securely. F) Upon a request, the service center 910 verifies and prints out a paper copy of the document with an optical sensitive component that is generated by the service center 910 for that document. The optical sensitive component is coupled with the last signer's e-seal.

For the case of multiple signers for an official document, the system server of an organization can be used rather than a service center and involves the following steps:.

A) An official document (e.g. a design document of a building) is created by a proposer.

B) The proposer logs into the system server. With that person's private key, the proposer signs and sends the document to the next person for verification/approval through the system server.

C) The system server notifies the next person of the arrival of the document, and the person signs the document.

D) The system server creates a record of the document and files the record for further verification.

E) The final signed document is filed in an archive of the organization.

F) Upon request, the system server verifies and prints out a paper copy of the document. The printed copy has optical sensitive component added to the document. The optical sensitive component is from the system server, designed for this particular document, and coupled together with an e-seal of the last signer.

The embodiments of the invention are preferably implemented using general-puφose computers. In particular, the processing or functionality of Figs. 1-9 can be implemented as software, or a computer program, executing on a computer. The method or process steps of protecting the legitimacy of electronic and conesponding printed documents are effected by instructions in the software that are carried out by the computer. The software may be implemented as one or more modules for implementing the process steps. A module is a part of a computer program that usually performs a particular function or related functions. Also, as described hereinbefore, a module can also be a packaged functional hardware unit for use with other components or modules.

In particular, the software may be stored in a computer usable or readable medium, including a floppy disc, a hard disc drive, a magneto-optical disc drive, CD-ROM, magnetic tape or any other of a number of non-volatile storage devices well known to those skilled in the art. The software is preferably loaded into the computer from the computer usable medium and then carried out by the computer. A computer program product includes a computer usable medium having such software or a computer program recorded on the medium that can be carried out by a computer. The use of the computer program product in the computer preferably effects an advantageous system for virtual commodity trading.

The computer system can be connected to one or more other computers via a communication interface using an appropriate communication channel such as a modem communications path, a computer network, or the like. The computer network may include a local area network (LAN), a wide area network (WAN), an Intranet, and/or the Internet.

Numerous configurations of computer systems can be employed without departing from the scope and spirit of the invention. Computers with which the embodiment can be practiced include IBM-PC/ATs or compatibles, the Macintosh (TM) family of PCs, Sun Sparcstation (TM), a workstation or the like. The foregoing is merely exemplary of the types of computers with which the embodiments of the invention may be practiced.

Typically, the processes of the embodiments are resident as software or a program recorded on a hard disk drive as the computer readable medium, and read and controlled using the computer system. In some instances, the program may be supplied to the user encoded on a CD-ROM or a floppy disk, or alternatively could be read by the user from the network via a modem device connected to the computer, for example. Still further, the software can also be loaded into the computer system from other computer readable medium including magnetic tape, a ROM or integrated circuit, a magneto-optical disk, a radio or infra-red transmission channel between the computer and another device, a computer readable card such as a PCMCIA card, and the Internet and Intranets including email transmissions and information recorded on web sites and the like. The foregoing is merely exemplary of relevant computer readable mediums. Other computer readable mediums may be practiced without departing from the scope and spirit of the invention.

Thus, an electronic document and a printed document capable of having their legitimacy protected, and a method, an apparatus, a computer program product and a system for protecting the legitimacy of electronic and printed documents are described. While only a small number of embodiments are described, it will be apparent to those skilled in the art, in view of this disclosure, that numerous changes and/or modifications can be made without departing from the scope and spirit of the invention.

Claims

1. An electronic document for reproduction of a conesponding printed document capable of having the legitimacy of said electronic document protected, said printed document being a printed version of said electronic document, said electronic document including: content of an original document in electronic form; a content digest for said content said original document in electronic form; an electronic seal or e-seal for authenticating said original document in electronic form, said e-seal including a visible seal of an authority and said content digest embedded in said visible seal; an optically sensitive or sensible component added to said authenticated document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document.

2. The electronic document according to claim 1, further including a watermark in said e-seal for embedding said content digest in said visible seal.

3. The electronic document according to claim 2, wherein said content digest is encrypted prior to watermarking said visible seal.

4. The electronic document according to claim 3, wherein at least one of an embedding address, shape, and boundary of said watermark is a key for encrypting said content digest, watermarking said e-seal, or both.

5. The electronic document according to claim 1, wherein said content digest is a condensed representation of said original document generated by a step selected from the group consisting of: hashing said content using a secure hashing process; selecting key items of said content; and extracting features of said content.

6. The electronic document according to claim 1, wherein said content digest is a condensed representation of said original document generated by block- wise digest derivation applied to said content, each block having a predetermined size and shape, said content digest including an anay of labels with each label being dependent upon a classification of a conesponding block of said content.

7. The electronic document according to claim 1, wherein said visible seal includes at least one of a document header, a logo or artwork, a graphical symbol, and a signature.

8. The electronic document according to claim 1, wherein said optically sensitive or sensible component includes a serial number for said electronic document.

9. The electronic document according to claim 1, wherein said electronic document includes: at least one of two or more pages and multimedia information in said content; and one or more landmarks for locating at least one of said content, said e-seal, and other document components.

10. The electronic document according to claim 1, further including a second e-seal having: content for said second e-seal including said content of said original document and said (first) e-seal; and a visible seal of an authority and a content digest dependent upon said content of said second e-seal embedded in said visible seal.

11. The electronic document according to claim 1 , further including an imperceptible watermark embedded in said e-seal for protecting ownership of the authority of said e-seal.

12. A printed document reproduced from an electronic document capable of having the legitimacy of said printed document protected, said printed document being a printed version of said electronic document, said printed document including: rendered content of an original document; an electronic seal or e-seal for authenticating said original document rendered in said printed document, said e-seal including a visible seal of an authority and a content digest for said content of said original document embedded in said visible seal; an optically sensitive or sensible component rendered in said authenticated document using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document.

13. The printed document according to claim 12, further including a watermark in said rendered e-seal for embedding said content digest in said visible seal.

14. The printed document according to claim 13, wherein said content digest is encrypted prior to watermarking said visible seal.

15. The printed document according to claim 14, wherein at least one of an embedding address, shape, and boundary of said watermark is a key for encrypting said content digest, watermarking said e-seal, or both.

16. The printed document according to claim 12, wherein said content digest is a condensed representation of said original document generated by a step selected from the group consisting of: hashing said content using a secure hashing process; selecting key items of said content; and extracting features of said content.

17. The printed document according to claim 12, wherein said content digest is a condensed representation of said original document generated by block- wise digest derivation applied to said content, each block having a predetermined size and shape, said content digest including an anay of labels with each label being dependent upon a classification of a conesponding block of said content.

18. The printed document according to claim 12, wherein said rendered visible seal includes at least one of a document header, a logo or artwork, a graphical symbol, and a signature.

19. The printed document according to claim 12, wherein said optically sensitive or sensible component includes a serial number for said printed document.

20. The printed document according to claim 12, wherein said electronic document includes: at least one of two or more pages and multimedia information in said content; and one or more landmarks for locating at least one of said content, said e-seal, and other document components.

21. The printed document according to claim 12, further including a second rendered e-seal having: content for said second e-seal including said content of said original document and said (first) e-seal; and a visible seal of an authority and a content digest dependent upon said content of said second e-seal embedded in said visible seal.

22. The printed document according to claim 12, further including an imperceptible watermark embedded in said e-seal for protecting ownership of the authority of said e-seal.

23. A method of protecting the legitimacy of an electronic document and a corresponding printed document, said printed document being a printed version of said electronic document, said method including the steps of: generating a content digest for an original document in electronic form; authenticating said original document in electronic form using an electronic seal or e-seal, said e-seal including a visible seal of an authority and said content digest embedded in said visible seal; adding an optically sensitive or sensible component to said authenticated document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document.

24. The method according to claim 23, wherein said authenticating step includes the step of watermarking said visible seal with said content digest to embed said content digest in said visible seal.

25. The method according to claim 24, wherein said authenticating step includes the step of encrypting said content digest prior to watermarking said visible seal.

26. The method according to claim 25, wherein at least one of an embedding address, shape, and boundary of said watermark is a key for encrypting said content digest, watermarking said e-seal, or both..

27. The method according to claim 23, wherein said content digest is a condensed representation of said original document generated by a step selected from the group consisting of: hashing said content using a secure hashing process; selecting key items of said content; and extracting features of said content.

28. The method according to claim 23, wherein said content digest is a condensed representation of said original document generated by block-wise digest derivation applied to said content, each block having a predetermined size and shape, said content digest including an anay of labels with each label being dependent upon a classification of a conesponding block of said content.

29. The method according to claim 23, wherein said visible seal includes at least one of a document header, a logo or artwork, a graphical symbol, and a signature.

30. The method according to claim 23, wherein said optically sensitive or sensible component includes a serial number for said electronic document.

31. The method according to claim 23, wherein said electronic document includes: at least one of two or more pages and multimedia information in said content; and one or more landmarks for locating at least one of said content, said e-seal, and other document components.

32. The method according to claim 23, further including a second e-seal having: content for said second e-seal including said content of said original document and said (first) e-seal; and a visible seal of an authority and a content digest dependent upon said content of said second e-seal embedded in said visible seal.

33. The method according to claim 23, further including the step of embedding an imperceptible watermark in said e-seal for protecting ownership of the authority of said e-seal.

34. An apparatus for protecting the legitimacy of an electronic document and a conesponding printed document, said printed document being a printed version of said electronic document, said apparatus including: means for generating a content digest for an original document in electronic form; means for authenticating said original document in electronic form using an electronic seal or e-seal, said e-seal including a visible seal of an authority and said content digest embedded in said visible seal; means for adding an optically sensitive or sensible component to said authenticated document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document.

35. The apparatus according to claim 34, wherein said authenticating means includes means for watermarking said visible seal with said content digest to embed said content digest in said visible seal.

36. The apparatus according to claim 35, wherein said authenticating means includes means for encrypting said content digest prior to watermarking said visible seal.

37. The apparatus according to claim 36, wherein at least one of an embedding address, shape, and boundary of said watermark is a key for encrypting said content digest, watermarking said e-seal, or both.

38. The apparatus according to claim 34, wherein said content digest is a condensed representation of said original document generated by means selected from the group consisting of: means for hashing said content using a secure hashing process; means for selecting key items of said content; and means for extracting features of said content.

39. The apparatus according to claim 34, wherein said content digest is a condensed representation of said original document generated by means for block- wise digest derivation of said content, each block having a predetermined size and shape, said content digest including an anay of labels with each label being dependent upon a classification of a corresponding block of said content.

40. The apparatus according to claim 34, wherein said visible seal includes at least one of a document header, a logo or artwork, a graphical symbol, and a signature.

41. The apparatus according to claim 34, wherein said optically sensitive or sensible component includes a serial number for said electronic document.

42. The apparatus according to claim 34, wherein said electronic document includes: at least one of two or more pages and multimedia information in said content; and one or more landmarks for locating at least one of said content, said e-seal, and other document components.

43. The apparatus according to claim 34, further including a second e-seal having: content for said second e-seal including said content of said original document and said (first) e-seal; and a visible seal of an authority and a content digest dependent upon said content of said second e-seal embedded in said visible seal.

44. The apparatus according to claim 34, further including means for embedding an imperceptible watermark in said e-seal for protecting ownership of the authority of said e-seal.

45. A computer program product having a computer usable medium having a computer readable program code means embodied therein for protecting the legitimacy of an electronic document and a conesponding printed document, said printed document being a printed version of said electronic document, said computer program product including: computer readable program code means for generating a content digest for an original document in electronic form; computer readable program code means for authenticating said original document in electronic form using an electronic seal or e-seal, said e-seal including a visible seal of an authority and said content digest embedded in said visible seal; computer readable program code means for adding an optically sensitive or sensible component to said authenticated document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document.

46. The computer program product according to claim 45, wherein said computer readable program code means for authenticating includes computer readable program code means for watermarking said visible seal with said content digest to embed said content digest in said visible seal.

47. The computer program product according to claim 46, wherein said computer readable program code means for authenticating includes computer readable program code means for encrypting said content digest prior to watermarking said visible seal.

48. The computer program product according to claim 47, wherein at least one of an embedding address, shape, and boundary of said watermark is a key for encrypting said content digest, watermarking said e-seal, or both..

49. The computer program product according to claim 45, wherein said content digest is a condensed representation of said original document generated by computer readable program code means selected from the group consisting of: computer readable program code means for hashing said content using a secure hashing process; computer readable program code means for selecting key items of said content; and computer readable program code means for extracting features of said content.

50. The computer program product according to claim 45, wherein said content digest is a condensed representation of said original document generated by computer readable program code means for block- wise digest derivation of said content, each block having a predetermined size and shape, said content digest including an anay of labels with each label being dependent upon a classification of a conesponding block of said content.

51. The computer program product according to claim 45, wherein said visible seal includes at least one of a document header, a logo or artwork, a graphical symbol, and a signature.

52. The computer program product according to claim 45, wherein said optically sensitive or sensible component includes a serial number for said electronic document.

53. The computer program product according to claim 45, wherein said electronic document includes: at least one of two or more pages and multimedia information in said content; and one or more landmarks for locating at least one of said content, said e-seal, and other document components.

54. The computer program product according to claim 45, further including a second e-seal having: content for said second e-seal including said content of said original document and said (first) e-seal; and a visible seal of an authority and a content digest dependent upon said content of said second e-seal embedded in said visible seal.

55. The computer program product according to claim 45, further including computer readable program code means for embedding an imperceptible watermark in said e-seal for protecting ownership of the authority of said e-seal.

56. A system utilising a network for protecting the legitimacy of an electronic document and a conesponding printed document, said printed document being a printed version of said electronic document, said system including: means for generating a content digest for an original document in electronic form; means for authenticating said original document in electronic form using an electronic seal or e-seal, said e-seal including a visible seal of an authority and said content digest embedded in said visible seal; means for adding an optically sensitive or sensible component to said authenticated document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document.

57. The system according to claim 56, wherein said authenticating means includes means for watermarking said visible seal with said content digest to embed said content digest in said visible seal.

58. The system according to claim 57, wherein said authenticating means includes means for encrypting said content digest prior to watermarking said visible seal.

59. The system according to claim 58, wherein at least one of an embedding address, shape, and boundary of said watermark is a key for encrypting said content digest, watermarking said e-seal, or both.

60. The system according to claim 56, wherein said content digest is a condensed representation of said original document generated by means selected from the group consisting of: means for hashing said content using a secure hashing process; means for selecting key items of said content; and means for extracting features of said content.

61. The system according to claim 56, wherein said content digest is a condensed representation of said original document generated by means for block- wise digest derivation of said content, each block having a predetermined size and shape, said content digest including an array of labels with each label being dependent upon a classification of a conesponding block of said content.

62. The system according to claim 56, wherein said visible seal includes at least one of a document header, a logo or artwork, a graphical symbol, and a signature.

63. The system according to claim 56, wherein said optically sensitive or sensible component includes a serial number for said electronic document.

64. The system according to claim 56, wherein said electronic document includes: at least one of two or more pages and multimedia information in said content; and one or more landmarks for locating at least one of said content, said e-seal, and other document components.

65. The system according to claim 56, further including a second e-seal having: content for said second e-seal including said content of said original document and said (first) e-seal; and a visible seal of an authority and a content digest dependent upon said content of said second e-seal embedded in said visible seal.

66. The system according to claim 56, further including a trusted printing or reproduction device for printing said authenticated document containing said optical sensitive or sensible component.

67. The system according to claim 66, wherein said trusted printing or reproduction device is accessible via said network and is remotely located from one or more of the other components of said system.

68. The system according to claim 56, further including means for embedding an imperceptible watermark in said e-seal for protecting ownership of the authority of said e-seal.

69. A system for protecting the legitimacy of an electronic document and a conesponding printed document, said system including: means for generating an authenticated electronic document, said authenticated electronic document including content of an original document in electronic form, an electronic seal or e-seal for authenticating said original document in electronic form, said e-seal including a visible seal of an authority and a content digest embedded in said e-seal; means for generating an optically sensitive or sensible component added to said authenticated electronic document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document; means for verifying the legitimacy of said authenticated electronic document; means for printing said authenticated electronic document and said optically sensitive component using said trusted printing process dependent upon said verifying means to provide an authenticated printed document.

70. The system according to claim 69, wherein said legitimacy verifying means includes means for verifying a watermarked digest of content against a conesponding one of one or more e-seals included in said authenticated electronic document.

71. The system according to claim 70, wherein said legitimacy verifying means further includes means for locating and verifying one or more e-seals in said authenticated electronic document.

72. The system according to claim 70, wherein said legitimacy verifying means further includes means for verifying the validity of each of one or more e-seals included in said authenticated electronic document.

73. The system according to claim 69, further including: means for verifying the legitimacy protection of said authenticated printed document based on said electronic document.

74. The system according to claim 73, wherein said means for verifying the legitimacy protection said authenticated printed document further including: means for visually inspecting said visual seal of each of said one or more e- seals; means for verifying said optically sensitive component of said authenticated printed document; means for scanning said authenticated printed document and extracting a watermark from each of said one or more e-seals; and means for extracting a content digest from each of said watermarks and verifying said extracted content digest.

75. A method for protecting the legitimacy of an electronic document and a conesponding printed document, said method including the steps of: generating an authenticated electronic document, said authenticated electronic document including content of an original document in electronic form, an electronic seal or e-seal for authenticating said original document in electronic form, said e-seal including a visible seal of an authority and a content digest embedded in said e-seal; generating an optically sensitive or sensible component added to said authenticated electronic document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document; verifying the legitimacy of said authenticated electronic document; printing said authenticated electronic document and said optically sensitive component using said trusted printing process dependent upon said verifying step to provide an authenticated printed document.

76. The method according to claim 75, wherein said legitimacy verifying step includes the step of verifying a watermarked digest of content against a conesponding one of one or more e-seals included in said authenticated electronic document.

77. The method according to claim 76, wherein said legitimacy verifying step further includes the steps of locating and verifying one or more e-seals in said authenticated electronic document.

78. The method according to claim 76, wherein said legitimacy verifying step further includes the step of verifying the validity of each of one or more e-seals included in said authenticated electronic document.

79. The method according to claim 75, further including a step of verifying the legitimacy protection of said authenticated printed document based on said electronic document.

80. The method according to claim 79, wherein said step for verifying the legitimacy protection said authenticated printed document further includes the steps of: visually inspecting said visual seal of each of said one or more e-seals; verifying said optically sensitive component of said authenticated printed document; scanning said authenticated printed document and extracting a watermark from each of said one or more e-seals; and extracting a content digest from each of said watermarks and verifying said extracted content digest.

81. A computer program product having a computer usable medium having a computer readable program code means embodied therein for protecting the legitimacy of an electronic document and a conesponding printed document, said computer program product including: computer readable program code means for generating an authenticated electronic document, said authenticated electronic document including content of an original document in electronic form, an electronic seal or e-seal for authenticating said original document in electronic form, said e-seal including a visible seal of an authority and a content digest embedded in said e-seal; computer readable program code means for generating an optically sensitive or sensible component added to said authenticated electronic document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document; computer readable program code means for verifying the legitimacy of said authenticated electronic document; computer readable program code means for printing said authenticated electronic document and said optically sensitive component using said trusted printing process dependent upon said computer readable program code means means for verifying to provide an authenticated printed document.

82. The computer program product according to claim 81 , wherein said computer readable program code means for verifying legitimacy includes computer readable program code means for verifying a watermarked digest of content against a conesponding one of one or more e-seals included in said authenticated electronic document.

83. The computer program product according to claim 82, wherein said computer readable program code means for legitimacy verifying further includes computer readable program code means for locating and verifying one or more e-seals in said authenticated electronic document.

84. The computer program product according to claim 82, wherein said computer readable program code means for legitimacy verifying further includes computer readable program code means for verifying the validity of each of one or more e-seals included in said authenticated electronic document.

85. The computer program product according to claim 81 , further including: computer readable program code means for verifying the legitimacy protection of said authenticated printed document based on said electronic document.

86. The computer program product according to claim 85, wherein said computer readable program code means for verifying the legitimacy protection said authenticated printed document further including: computer readable program code means for visually inspecting said visual seal of each of said one or more e-seals; computer readable program code means for verifying said optically sensitive component of said authenticated printed document; computer readable program code means for scanning said authenticated printed document and extracting a watermark from each of said one or more e-seals; and computer readable program code means for extracting a content digest from each of said watermarks and verifying said extracted content digest.

87. A method of trusted document delivery via a network, said method including the steps of: establishing a secure communication link between parties at one or more locations; verifying the identity of each party; providing means for a party to sign an original document; protecting the legitimacy of a signed document in electronic form, said protected signed document including content of an original document in electronic form, a content digest for said content of said original document in electronic form, and an electronic seal or e-seal for authenticating said original document in electronic form, said e-seal including a visible seal of an authority and said content digest embedded in said visible seal; sending a protected, signed electronic document from a sending party at a first location to a receiving party at a second remote location of said network; notifying said receiving party of said sent protected electronic document; receiving said sent protected electronic document at said second remote location of said network; and sending a receipt of said sent protected electronic document to said sending party at said first location.

88. The method according to claim 87, further including the steps of: verifiying the legitimacy of said sent protected electronic document at said second remote location of said network to ensure the legitimacy of a document to be printed; adding an optically sensitive or sensible component to said authenticated document for printing using a trusted printing process, said optically sensitive or sensible component containing information for indicating copying or modification of said printed document in a copy or modified version of said printed document; printing a copy of said protected electronic document using a trusted printing process.

89. The method according to claim 87, further being a certification / notarization method including the steps of: establishing a secure network with an issuer, an owner and the recipient of the document; obtaining an electronic document for an owner and assigning a trust statement to the document; delivering a trusted copy of the document to the recipient.

90. The method according to claim 89, further including the step of providing an electronic safe deposit box for storage of electronic certificates.

91. The method according to claim 87, further being an electronic check transacting method including the steps of: establishing a secure network link from a service center to a payee, a payer, and one or more respective banks; signing an electronic check and sending said check to the payee, said check being said signed electronic document; claiming said check for the payee; clearing the transaction; and refusing the payment if the check is not legitimate.

92. The method according to claim 87, being a method for signing of documents with multiple signing parties including the step of: establishing a secure network link between a service center and signers; freezing an agreed version of said electronic document; and signing said electronic document in either a serial or parallel manner.

93. The method according to claim 87, further including the step of converting said original document in printed form to said original document electronic form using a scanning process.

94. The method according to claim 87, further including the step of verifying the legitimacy of said sent protected electronic at a location of said network.

95. The method according to claim 87, further including the step of providing means for a party to sign said original document.