IC CARD FOR ENCRYPTION OR DECRYPTION PROCESSING, AND ENCRYPTION COMMUNICATION SYSTEM AND ENCRYPTION COMMUNICATION METHOD EMPLOYING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an encryption communication system and encryption communication method capable of flexibly coping with it, even when members in a group are changed and securing full security, when carrying out encryption communication among members in the group.;SOLUTION: IC cards for storing the same fixed code F(a) are supplied to all the employees of an enterprise A. When encryption communication between the employees B, C belonging to the same project group is conducted, the sender side employee B writes an optional variable code V(1) to the IC card 100a, wherein encryption key information K(a1) is generated on the basis of the codes F(a), V(1) and the IC card 100a encrypts data D1 by using the information K(a1). The recipient-side employee C writes the variable code V(1) delivered from the employee A to the IC card 100b, wherein the encryption key information K(a1) is generated. The IC card 100b uses the information K(a1), to decrypt received encrypted text data D2 and to obtain data D3. Different fixed codes F(a) are supplied to different enterprises and formed write disabled, to secure security.;COPYRIGHT: (C)2006,JPO&NCIPI