Patent ID: 6011848
Filing Date: 2000-01-04
Classification: G06Q,H04L

Abstract:
A message delivery method in a system containing at least an information provider and a user for a case in which the user receives a message from the information provider, the method comprising:(a) a step in which the information provider carries out a user authentication of the user according to a zero knowledge interactive proof protocol using check bits E generated according to a work key W and transmits to the user a ciphertext C and the check bits E, the ciphertext C containing a message M to be delivered to the user which is enciphered according to a secret key cryptosystem by using the work key W;(b) a message take out process in which the user takes out the work key W by using at least the check bits E, and obtains the message M by deciphering the ciphertext C according to the secret key cryptosystem by using the work key W.