초록 ▼

Encryption systems typically rely on the distribution of cipher keys between terminals for scrambling and unscrambling transmitted messages. Elaborate security precautions are necessary to protect the cipher keys since a compromise of the key could result in a compromise of the transmission. There i

Encryption systems typically rely on the distribution of cipher keys between terminals for scrambling and unscrambling transmitted messages. Elaborate security precautions are necessary to protect the cipher keys since a compromise of the key could result in a compromise of the transmission. There is disclosed a key distribution method and apparatus which uses a channel from identified terminals to a central key distribution center for the establishment, on a one-session basis, of the key which is to be used for the next session between those terminals. The key establishing link is itself encoded using a cipher key which changes after each usage. Provision is made to verify, for each new connection, that a compromise has not priorly occurred.

대표청구항 ▼

A key distribution method for communicating cipher keys between two terminals via a key distribution center, KDC, said method comprising establishing between any one terminal and said key distribution center a terminal-unique cipher key for controlling the generating of session keys, cooperating by

A key distribution method for communicating cipher keys between two terminals via a key distribution center, KDC, said method comprising establishing between any one terminal and said key distribution center a terminal-unique cipher key for controlling the generating of session keys, cooperating by transmitting information using said established terminal-unique cipher key between said KDC and said one terminal on a subsequent connection between said KDC and said one terminal to establish a session key for use by said one terminal in a subsequent secure transmission between said one terminal and a second terminal, and changing said priorly established terminal-unique cipher key in response to use of said priorly established terminal-unique cipher key on said subsequent connection between said one terminal and said KDC.