| 摘要 |
PROBLEM TO BE SOLVED: To provide an encryption technique excellent in the reduction of a secret information management load in each user, while guaranteeing an appropriate high speed of encryption processing.SOLUTION: In an encryption processing method, an output value of a one-way function related to public information of an opposite communication party and secret information of the self is used as a key in each terminal 10 mutually communicating. At message transmission, a target message is encrypted using the key to transmit to a predetermined server 20. Also, at message reception, a re-encrypted message destined to the terminal with exchangeability is received from the server 20, so that the received message is decrypted using the self-key. |
