Patent ID: 6873706

Claim:
A processing apparatus of secret information constructed by an arithmetic operation processing circuit, a storing circuit, and a signal line connecting said processing and storing circuits, in which said processing apparatus of the secret information obtains a same processing result as would be obtained by processing the secret information and data as a processing target by a conventional processing method, wherein said storing circuit holds: secret information forming information different from said secret information, and secret information forming information processing means for outputting said processing result by using said secret information forming information and said data serving as a processing target without allowing said secret information to appear in said arithmetic operation processing circuit, said storing circuit, and said signal line, and said arithmetic operation processing circuit executes said secret information forming information processing means, wherein said storing circuit further has converting means for converting said secret information forming information into another secret information forming information, and said another secret information forming information is information for allowing said secret information forming information processing means to output said same processing result.