| 摘要 |
PROBLEM TO BE SOLVED: To enhance the confidentiality an IC card and IC card system, using an enciphering method of a common key, a public key and a secret key. SOLUTION: A public key register 115 is transferred to another party, an another party public key register 117 on the transmission side and the public key register 115 on the reception side are stored in the second common key generation register, a common key 108 is generated from the first common key generation value register 103 and the second common key generation value register 104 on the basis of common key generation information 106, the common key generation information 106 is transferred to the other party, and a common key whose value is shared by the other party is generated. It becomes possible to improve the confidentiality of an IC card 100 and an IC card system using the IC card 100, by making the common key 108 a key of a common key ciphering system and performing enciphering through combining it with the public key ciphering system. |
