Encryption key processing system to be incorporated into data recovery system or key setting system for generating encryption key

摘要

An encryption key processing system includes a user terminal system which uses a key and a sub-system for holding information regarding the user terminal system, the sub-system generating predetermined public information, secret information corresponding to the public information and a secret key dependent on an identifier of said user terminal system, sending a secret key to the user terminal system in secret and the user terminal system generating and using a key and necessary information based on a secret key and public information received from the sub-system.