Patent ID: 6490685
Filing Date: 2002-12-03
Classification: G06F,G11C

Abstract:
A storage device, which is connectable to a computer and serves as an external memory device of a computer as a whole, comprising:first storage means for storing data; second storage means storing an encoded cryptographic key; third storage means storing decoding information to decode said cryptographic key; fourth storage means storing an arithmetic function to test said third storage means; and a controller including: writing means, responsive to a read instruction from the computer, for decoding said cryptographic key with the decoding information stored in said third storage means, encrypting data supplied from said computer with said cryptographic key as decoded and writing the encrypted data in said first storage means; reading means, in response to a write instruction from the computer, for decoding said cryptographic key with the decoding information stored in said third storage means, reading data from said first storage means, decrypting the read data with said cryptographic key as decoded and outputting the decrypted data to the computer; and comparing means, in response to a test instruction from a test device, for processing the decoding information stored in said third storage means, by using the arithmetic function stored in said fourth storage means, and for comparing a resultant value and an expected value with each other and outputting a comparison result to the test device.