摘要 |
A public key of A used for encryption when information is transmitted to a first communication terminal 100a is transmitted, a second communication terminal 100b receives the public key of A, a public key of B used for encryption when information is transmitted to the second communication terminal 100b in response to the reception of the public key of A, and the first communicatio n germinal 100a receives the public key of B. As a result, the public keys are exchanged between the first communication terminal 100a and the second communication terminal 100b, and consequently the public key is easily obtained.
|