Patent ID: 8726024

Claim:
A method of authenticating using a first device and a second device, wherein first identification information, a first key, and encrypted first secret identification information are stored in the first device, the first identification information and the first key are prohibited from being read from outside, and the encrypted first identification information is readable, and constant number information, second identification information, and a second key are stored in the second device, the method comprising: generating third secret identification information by decrypting the encrypted first identification information read from the first device by the second device; generating random number information by the second device; generating a third key by using the constant number information read from the second device and the first key by the first device; generating a fourth key by using the third key and the random number information by the first device; generating first authentication information by processing the first information with the fourth key in one-way function operation by the first device; generating a fifth key by using the second key and the random number information by the second device; generating second authentication information by processing the third identification information with the fifth key in one-way function operation by the second device; and determining whether the first authentication information and the second authentication information match by the second device.