Encrypted Data Administration Device Encrypted Data Administration Method And Encrypted Data Administration Program

Abstract: An objective of the present invention is to implement an invalidation protocol of a secret key which is usable even in a mathematical function encryption protocol. In an encryption processing system (10) an encryption protocol is used with which a secret key cannot be used to decrypt encrypted data when attribute information and key information which are set in the encrypted data do not correspond to attribute information and key information which are set in the secret key. An encrypted data administration device (200) is disposed which carries out a relay between a user terminal (100) which carries out data encryption and decryption and an encrypted data storage device (300) which stores the encrypted data. The encrypted data administration device (200) determines whether a user whose secret key is invalid is included among users who have attribute information which is set in the encrypted data which is acquired from the encrypted data storage unit (300) and sets to the encrypted data as the key information different values depending on the determination result. The encrypted data administration device (200) transmits to the user terminal (100) the encrypted data for which the key information is set.

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