ENCRYPTION SYSTEM KEY DISTRIBUTION METHOD AND APPARATUS

摘要

ENCRYPTION SYSTEM KEY DISTRIBUTION METHOD AND APPARATUS 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