CRYPTOGRAPHIC COMMUNICATION METHOD, CRYPTOGRAPHY METHOD AND CRYPTOGRAPHIC COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a cryptographic communication method by new ID-NIKS high in security, incapable of separating a secret key generation function and a key sharing function and capable of probabilistically sharing a key. SOLUTION: By using public keys intrinsic to respective entities and random numbers intrinsic to the respective entities based on the ID information of the respective entities, the two kinds of secret keys (vectors s and t) using two numbers as modulus are generated in a center 1 and sent to the respective entities. The respective entities use the two kinds of the sent secret keys intrinsic to the entities and the public key of the entity of a communication object opened to the public and generate a shared key shared between the entities of two persons to be used at the time of ciphering a plain text to a cipher text and at the time of deciphering the cipher text to the plain text.