| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a risk of solving and falsifying a call originator number and to reduce a management load related to a cryptographic key. SOLUTION: In an access point system 102, a caller number acquisition means 108 receives a caller number 115 from a public network 104 when the caller number arrives from a caller system. An encoding means 110 encodes this caller number 115 with a secret key 118 common in each access point system, and a transmission means 112 transmits the caller number 115 encoded by the encoding means 110 to a communication network 105. And, in an addressee system 103, a reception means 113 receives the encoded caller number 115 through the communication network 105, and a decoding means 114 receives the encoded caller number 115 from the reception means 113 and decodes it by using a public key 119. |
