| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an encrypted data delivery system etc. which encrypts data to securely deliver the data, can verify the integrity of data to be delivered and is effective to prevention of denial of the fact of data delivery. <P>SOLUTION: A transmitter for transmitting data and a receiver for receiving the data share a secret key, and data encrypted by the shared secret key is delivered. The transmitter transmits an MAC (Message Authentication Code) value calculated by using an HMAC (Keyed-Hashing for Message Authentication Code) key generated from unencrypted data and the shared secret key to the management server, and the receiver transmits a MAC value calculated by using a HMAC key generated from decrypted data and the shared secret key to the management server. The management server confirms the coincidence of the MAC values to thereby verify the integrity of the delivered data, and in combination with the verification, the manager of the management server being a third organization verifies the integrity, thereby the delivery fact can be prevented from being denied. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
