PURPOSE: To reduce the used capacity of a memory in an information processing terminal to generate plural keys for various applications.

CONSTITUTION: An IC card 200 transmits ID 10 from a memory 210 to an information processing terminal 100. The information processing terminal 100 uses a center key 11 stored in a memory 110 to operate the received ID 10 by a ciphering means 120 and obtains a base key 12 and stores it in a memory 130. A processing means 140 generates a session key 13 corresponding to various applications from the base key 12 and stores it in a memory 150.