Patent ID: 7660992
Filing Date: 2010-02-09
Classification: G06F,H04L

Abstract:
1. An electronic data storage system comprising: a file device for storing at least electronic data; and a data processing unit which generates a first check code for detecting falsification of said electronic data and a second check code for detecting falsification of a public key-based electronic signature using a secret encryption method and/or an encryption key when the electronic data is registered, stores said electronic data, said public key-based electronic signature, and said first and second check codes into said file device, wherein said data processing unit generates said first check code by an encrypting method unique to said system from said electronic data, an electronic signature for registration by encrypting a hash value of said electronic data with a secret key, and said second check code by an encrypting method unique to said system from said electronic signature for registration, and verifies the validity of said stored electronic data and said electronic signature by creating a third check code from said electronic data by said encrypting method unique to said system and a fourth check code from said electronic signature for registration by said encrypting method unique to said system, compares said stored first check code with said third check code and said stored second check code with said fourth check code, and outputs said electronic data, a second electronic signature created by encrypting said electronic data with a secret key which is valid at output time and said electronic signature for registration when said compared result is favorable.