Method and apparatus for encrypting/decrypting data

摘要

A computer system comprises a first computer entity (11) arranged to encrypt data using an encryption key comprising a time value, and a second computer entity (14) arranged to generate, at intervals, a decryption key using a current time value. The encryption and decryption processes are such that the decryption key generated using a current time value corresponding to that used for the encryption key, is apt to decrypt the encrypted s data.