Method for generating a cryptographic key to protect communication between two entities, computer program product, device adapted to generate a cryptographic key for a communications entity, user equipment, and system

摘要

A technique for generating a cryptographic key (120) is provided. The technique is particularly useful for protecting the communication between two entities (202, 302; 204, 304) cooperatively running a distributed security operation. The technique comprises providing at least two parameters (106, 108), the first parameter (106) comprising or deriving from some cryptographic keys (110, 112) which have been computed by the first entity (202, 302) by running the security operation; and the second parameter (108) comprising or deriving from a token (116) having a different value each time the security (114) operation is initiated by the second entity (204, 304) for the first entity (202, 302). A key derivation function is applied to the provided parameters (106, 108) to generate the desired cryptographic key (120).