PUBLIC KEY GENERATOR, SHARED KEY GENERATOR, KEY EXCHANGE DEVICE, AND KEY EXCHANGE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a public key generator, a shared key generator, a key exchange device and a key exchange method for keeping the key operation at the time of DH key exchange processing secret from a third person and by which appropriation or alteration of a major operation by the third person is extremely difficult.;SOLUTION: The public key generator is constituted so that a private key ka is used only for generation of the public key ya and the shared key Ka inside an LSI 31 and a main encryption operation of the key exchange device 33 is not leaked to the outside by integrating a random number generation means 11 for generating random numbers ka which satisfy 0kaq when defining an element on a finite group F in which multiplication is defined as g and defining an order being a prime number of the the element g as q, a public key generation means 12 for calculating the public key ya on the finite group F from the random numbers ka, the element g and the prime number q and outputting the calculated key, and a shared key generation means 21 for creating the shared key Ka based on a public key yb generated by a user 2 to be a public key distribution origin and a shared key distribution destination and the private key ka generated by the random number generation means 11 into one LSI 31.;COPYRIGHT: (C)2005,JPO&NCIPI