ENCRYPTION DEVICE, ENCIPHERING DEVICE, AND DECIPHERING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an encryption device, an enciphering device, and a deciphering device which are easily installed in an existing network system. SOLUTION: The encryption device is provided with an enciphering/ encapsulating processing part and a deciphering/decapsulating processing part. The enciphering/encapsulating processing part enciphers plain text data received from a plain text network and refers to a preliminarily determined correspondence relation between addresses and other encryption devices and performs encapsulating processing to newly set a header on the basis of an encryption device corresponding to the address set in the header of plain text data and transmits cipher data generated by this processing to a cipher text network of the same IP sub-network as the plain text network. The deciphering/ decapsuling processing part deciphers cipher data received from a cipher text network to plain text data and performs decapsulating processing to set a header again on the basis of the address set in the header of this plain text data and transmits plain text data generated by this processing to a plain network of the same IP sub-network as the cipher text network.