DATA ENCIPHERING DEVICE AND DATA DECIPHERING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a data enciphering device and a data deciphering device capable of suppressing expansion of circuitry even when an SPN-structured enciphering system provided with a circuit having both enciphering and deciphering functions is mounted. SOLUTION: By using conversion whose inverse conversion is equivalent to the conversion itself for a data conversion section, the one and the same data conversion section can be used for enciphering and deciphering. Thus, expansion of circuitry can be suppressed even when the circuit having both enciphering and deciphering functions is mounted. COPYRIGHT: (C)2003,JPO