Session data is encoded in a tag-length-value format and encrypted using a modified encryption key. A session cookie is then formed by concatenating the length of the length of the secret, the length of the secret, the secret itself, and the encoded and encrypted configuration data. The session cookie...http://www.google.de/patents/US7533260?utm_source=gb-gplus-sharePatent US7533260 - Method and apparatus for encoding and storing session data
