Session key

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A session key ( German  session key ) is a randomly generated key that only once (for a single connection, an e-mail is used, etc.) (see initialization ). It is used in particular with hybrid encryption . A session key is transmitted securely after it has been generated using an asymmetric encryption process , while the actual user data is transmitted symmetrically encrypted using the session key .

In the case of protocols used in practice, it is customary to renegotiate session keys regularly so that a compromised session key does not enable the data traffic of the respective channel to be deciphered over long periods of time.

In classic cryptography , for example in the rotor cipher machines used during the Second World War , these individually selected keys were referred to as “ saying keys ”.

Individual evidence

  1. ^ Johannes A. Buchmann: Introduction to Cryptography . Springer, 2001, ISBN 0-387-95034-6 , pp. 140 .