Encryption system, the encryption communication method, encryption devices, key generation apparatus, decoding apparatus, content server apparatus, program, storage medium

摘要

To provide an operational flexibility, the encryption communication technology that relies on predicate encryption. The conversion rule for converting the predicate information used predicate encryption algorithm predicate specifying information and attribute for the conversion rule information which defines the conversion rules for converting the attribute information used in predicate encryption algorithm attribute specification information conversion rule information pair is a pair of the predicates for the conversion rule information which defines is predetermined. Is obtained first predicate information or first attribute information from the input information by using the conversion rule information of one included in the conversion rule information pairs. This information is used for encryption processing. In the decoding process, using the decryption key made by using the second predicate information or the second attribute information obtained from the user information using the conversion rule information of the other process for decrypting information.