Patent ID: 6256391
Filing Date: 2001-07-03
Classification: G06F,G11B,H04L

Abstract:
An information processing system, comprising:a plurality information processing apparatus connected to each other by a bus;said information processing apparatus including first information processing apparatus each having a function whose change is not open to a user, and second information processing apparatus each having a function whose change is open to a user;each of said first information processing apparatus including:receiving means for receiving enciphered data;first generating means for generating a first information;second generating means for generating a second information;first producing means for producing a cryptographic key using the first information generated by said first generating means and the second information generated by said second generating means; anddeciphering means for deciphering said received enciphered data using said cryptographic key, wherein said cryptographic key is changed at a predetermined timing while the data is being deciphered in accordance with a change in said second information; andeach of said second information processing apparatus including:first receiving means for receiving enciphered data;first generating means for generating the first information;second generating means for generating the second information;first producing means for producing a first cryptographic key using one of the first information generated by said first generating means and the second information generated by said second generating means, said second information being changed at a predetermined timing while the data is deciphered;second producing means for producing a second cryptographic key using the other of the first information generated by said first generating means and the second information generated by said second generating means;deciphering means for deciphering the enciphered data received by said receiving means using the first cryptographic key; andsecond deciphering means for further deciphering the data deciphered by said first deciphering means using the second cryptographic key.