DE4413678C1 - Electronic registration method during data transmission - Google Patents

Abstract

The invention relates to an electronic registration method in which a data record (m) to be transmitted from a document is signed and certified, a data record (u(1)) of a personal signature is stored protected with a signature certificate (Zu(1)), the data records (m, u(1)), the two certificates (Zm, Zu(1)) and the associated keys (pk(1), pk(Z)) are transmitted to a receiving station where the data records (m, u(1)) with the certificates (Zm, Zu(1)) are checked for integrity, a data record (q) of an acknowledgement which is to be transmitted back is signed and certified and transmitted analogously to the document data record with a further protected signature data record (u(2)) and checked. <IMAGE>

Description

The invention relates to a registration procedure for an elek tronically transmitted document.

By using remote copiers, documents can be transferred to elec tronic way. Such documents will be but not recognized as legally binding, as transmission mani populations cannot be excluded. Such manipul lations are, for example, copying the sub written by a person who has never seen the document.

Electronic registration is known (DE-B .: Bitzer, Wolfgang: Encrypted text transmission. In: NTG- Technical reports, vol. 74, text and image communication, UDE publishing house GmbH, Berlin, 1980, pages 109 to 117), in which the to transferring text to a key distribution center Recipient is transmitted. In the key distribution center the text is signed with an electronic signature. As a proof of receipt, the signature can be sent as a receipt Key distribution center can be sent back to the sender.

A system for authentication is known from EP 05 47 837 A2 known, in which on the sheet of text to be transferred Signature is applied.

The invention has for its object an electronic To indicate the registration procedure for such a document at which the signatures for the document and the receipt are transmitted in a forgery-proof manner.

This object is achieved by the in patent claim 1 specified features solved.  

In the following the invention with reference to one in the drawing illustrated embodiment described.

In the single figure, some are hard as a block diagram goods components are shown, based on which the implementation of the method according to the invention is explained. It will be there assumed that a document from station A to a station B is transmitted. For this, station A a facsimile machine FK1 and station B a facsimile machine FK2 on. There is also a data backup in station A. direction DE1 and in station B a data backup direction DE2 provided. With the data backup device DE1 is contacted to a chip card CK1, so that a change  data exchange between the data backup device device DE1 and the chip card CK1 can be performed. Ana log is also on the receiving side a chip card CK2 with the Data protection device DE2 contacted.

In the transmitter-side station A in the remote copier FK1 a document record, not shown, a document record m educated. This data record m becomes the data backup device device DE1 transmitted and there before sending to station B processed.

The author of the document belonging to data set m has the Chip card CK1 with the data protection device DE1 contact animals. This chip card CK1 is a crypto, for example chip card, and the author has known himself through a security method, such as a PIN (personal identification number), a password or a biometric process compared to the CK1 and the Data backup device DE1 identified.

The document record m will be in the data backup direction DE1 itself or in the chip card CK1 signed, d. H. the data record m is, for example, a hash procedure Ren won a signature Sm. To perform this ope ration on the chip card CK1, this must be a corresponding Have computing capacity.

For example, a secret and are on the chip card CK1 a public key sk (1), pk (1) saved by the author chert. These two keys sk (1), pk (1) (secrete key, public key) and their properties are part of the known as the public key method.

The Urhe's signature is also on the CK1 chip card saved. This signature was, for example by scanning the original signature of the author and saved in digitized form as data record u (1)  chert. There is a public key on the chip card CK1 pk (Z) saved. This key pk (Z) belongs to one secret key sk (Z) with which, for example, in a Zer certification body secured the personal signature the chip card CK1 has been saved. To secure was in the certification body from the signature record u (1) using a hash method h computes a signature Su (1). With the secret key sk (Z) of the certification body was made from the signature signature Su (1) by a asymmetric cryptographic procedure a certificate zu (1) ge forms. This certificate Zu (1) is also on the chip Card CK1 saved.

The signature Sm of the document data record m becomes Help of the author's secret key sk (1) by the asym metric cryptographic process won a certificate Zm.

From the data backup device DE1 of station A. the following data to the data backup device DE2 of Sta tion B sent: The document record m, the signature ten data record u (1), the certificate Zm and the certificate To (1), as well as to the secret keys sk (1) and sk (Z) belonging public key pk (1) and pk (Z) of the Urhe bers and the certification body.

When using the asymmetric encryption method the public key pk (1) to the certificate Zm, and the public key pk (Z) to the certificate Zu (1) proper keys, because only with them from the certificates Zm, The corresponding signatures Sm, Su (1) are recovered for (1) can be.

Within the data backup device DE2 and / or on the Station B chip card CK2 will do the following checks performed.  

In a first step, the received signature Record u (1) with the certificate Zu (1) for integrity checked. For this purpose, the data set u (1) is used via the hashver drive h received the signature Su (1) at the receiving end. On A second way is this signature Su (1) via the public key pk (Z) obtained from certificate Zu (1). At Equality between these two obtained signatures Su (1) can be determined the integrity of the signature or the associated Da sentence u (1) can be closed.

In a second step, the received document data set m checked for intactness with the Zm certificate. For this purpose, the hash method h is used to convert the data set m into the Signature Sm calculated. In a second way, this is Signature Sm via the public key pk (1) from the Certificate Zm formed. If these two signatures are identical ren Sm can check the integrity of the document or the associated record m are closed.

The data is then from the data backup device DE2 sentences m, u (1) of the document and the signature to the Remote copier Fk2 given. Then on the facsimile machine Fk2 the document reproduced from the data set m together with the signature reproduced from data set u (1) be printed. Also a written representation on one Screen is possible.

The method according to the invention ensures that the one shown on the reception side with a signature seen document with the signature of the actual original bers is signed.

In a variant of this process section is in the sending station A a signature Sm 'from the document too together with the signature record m, u (1) formed. Out this signature Sm 'is with the secret key sk (1) of Creator's certificate Zm ′ calculated. In the receiving  Station B is then tested with these values leads.

To implement the enrollment process, the Sta tion B automatically after receipt of the signed document mentes and its review one by a recipient under transfer the written receipt back to station A.

For this purpose, station B a data record q is generated from a receipt (not shown) det. This receipt data record q becomes a data backup device DE2 transmitted and there before sending Station A edited.

The recipient who received the document from station A. and signed the receipt, did the same as the Author in station A, opposite the chip card CK2 and the Data backup device DE2 in station B identifi graces.

The receipt data record q is in the data backup device tung DE2 itself or in the chip card CK2 signed, d. H. out The data record q becomes a signature by the hashing method h Sq won. To perform this operation on the chip Card CK2 must have a corresponding computing capacity point.

There is a secret and a public one on the chip card CK2 Key sk (2), pk (2) of the recipient saved. Is further on the chip card CK2 the signature of the recipient saves. This signature became analogous to that of Urhe bers won and digitized as data set u (2) saved. The public card is also on the CK2 chip card Key pk (Z) of the certification body (it can be they are the same trustworthy entity the author's signature on the CK1 si chip card cherte), from which the personal signature  of the receiver saved on the chip card CK2 has been. To ensure security was in the certification body the signature data record u (2) with a hash method h a signature Su (2) is calculated. With the secret key sk (Z) of the certification body was created from the signature Signature Su (2) by an asymmetrical encryption process Certificate to (2) formed. This certificate to (2) is flat if stored on the chip card CK2.

The signature Sq of the receipt data record q becomes with With the help of the recipient 's secret key sk (2) asymmetric cryptographic process won a certificate Zq.

From the data backup device DE2 of station B. following data to the data backup device DE1 of Sta tion A sent: The receipt record q, the signature ten data record u (2), the certificate Zq and the certificate To (2) and to the secret keys sk (2) and sk (Z) belonging public key pk (2) and pk (Z) of the recipient gers and the certification body.

When using the asymmetric encryption method the public key pk (2) that corresponds to the certificate Zq appropriate keys, because only with him from the certificate Zq the corresponding signature Sq can be recovered.

Within the data backup device DE1 and / or on the Station A's chip card CK1 will perform the following checks gene made.

In a first step, the received signature Record u (2) with the certificate Zu (2) for integrity checked. For this purpose, the data record u (2) is used via the hashver drive h received the signature Su (2) at the receiving end. On A second way is this signature Su (2) via the public key pk (Z) obtained from certificate Zu (2). At Equality between these two signatures Su (2) can be determined  the integrity of the signature or the associated Da sentence u (2) can be closed.

In a second step, the receipt data received sentence q with the certificate Zq checked for intactness. For this purpose, the hash method h is used to convert the data set q Signature Sq calculated. In a second way, this is Signature Sq on the public key pk (2) from the Certificate Zq formed. If these two signatures are identical ren Sq can to the integrity of the receipt or the associated data record q are closed.

The data is then from the data backup device DE1 sentences q, u (2) of the receipt and the signature to the distance copier Fk1 given. Then on the remote copier Fk1 receipt reproduced from data set q together with the reproduced signature from data set u (2) be printed. Also a written representation on one Screen is possible.

The method according to the invention ensures that the one shown on the reception side with a signature seen receipt with the signature of the actual emp is signed.

In a variant of this process section is in the receiving station B a signature Sq 'from the receipt record together with the signature data set q, u (2). From this signature Sq ′, the secret key sk (2) the recipient's certificate Zq 'is calculated. In which the quit device receiving station A is then the test with these Values carried out.

If the transmission path for the document record m from station A to station B by a cryptological process ren, for example by an asymmetrical or a symme trical encryption process, is secured, is  this transmission process of delivery in the closed and equate sealed envelope. This is done at for example, in the data backup device DE1 the station A encrypted the document record m for Transfer station B and there in the data backup Tung DE2 decrypted. It can also transmit the others NEN records between stations A and B, for example the receipt record q or the signature records u (1) or u (2) are encrypted.

Claims (4)

1. Electronic registration procedure for the digital transmission of a document, in which the following steps are carried out one after the other:
In a transmitting station (station A), a document signature (Sm) is formed from a data record (m) of the document to be transmitted,
a document certificate (Zm) is formed from the signature (Sm) by a crypting process,
a data record (u (1)) of a personal signature of the author of the document is saved with a signature certificate (Zu (1)),
the document and the signature data record (m, u (1)), the two certificates obtained from it (Zm, Zu (1)) and the associated key (pk (1), pk (Z)) become a receiving station ( Station B) transmitted,
there the signature data record (u (1)) with the signature certificate (Zu (1)) and then the document data record (m) with the document certificate (Zm) each by calculating the associated signatures (Su ( 1), Sm) checked for integrity,
the data records (m, u) of the document and the signature are output in legible form,
an acknowledgment signature (Sq) is formed from a data record (q) of a receipt to be transmitted,
an acknowledgment certificate (Zq) is formed from this signature (Sq) by a crypting process,
a further data record (u (2)) of a personal signature of the recipient is saved with a further signature certificate (Zu (2) is saved,
the receipt and the further signature record (q, u (2)), the two certificates obtained from it (Zq, Zu (2)) and the associated key (pk (2), pk (Z)) become the sending station Transfer back (station A),
there the further signature record (u (2)) with the further signature certificate (Zu (2)) and then the receipt record (q) with the receipt certificate (Zg) each by calculating the associated signatures (see below) (2), Sq) checked for integrity, and
the data records (q, u (2)) of the receipt and the further signature are output in legible form. 2. Electronic registration procedure according to claim 1, where the document signature (Sm ') from the document too together with the signature record (m, u (1)) and the Acknowledgment signature (Sq ′) from the receipt together with the another signature record (q, u (2)) are formed. 3. Electronic enrollment process according to claim 1 or 2 where the signature is a signature record (u (1), u (2)) in a chip card (Ck1, CK2) secured with a Zer certificate (Zu (1), Zu (2)) together with the associated key sel (pk (Z)) is stored. 4. Electronic registration procedure according to one of the claims che 1 to 3 in which at least the document data record (m) is encrypted is transmitted.