Patent ID: 6351536
Filing Date: 2002-02-26
Classification: G06F,H04L

Abstract:
A method of transmitting ciphertext from a first device to a second device which is connected to the first device by a network, and deciphering the ciphertext in the second device, comprising:the step of transmitting the ciphertext and an identifier thereof from the first device to the second device; the step in the second device of generating, in accordance with a first key generation program for generating a pair of a first public key and a first secret key in a first public-key cryptosystem, the pair of the first public key and the first secret key, and holding the generated first secret key in correspondence with the identifier; the step of transmitting the generated first public key and the identifier from the second device to the first device; the step in the first device of enciphering information relating to the decryption of the ciphertext using the received first public key, and transmitting the enciphered information and the identifier to the second device; and the step in the second device of deciphering the received enciphered information using the first secret key, which corresponds to the received identifier, of the held first secret keys, and deciphering the ciphertext utilizing the deciphered information.