ENCRYPTION COMMUNICATION SYSTEM, COMMUNICATION DEVICE, KEY DISTRIBUTION DEVICE, ENCRYPTION COMMUNICATION METHOD

摘要

A cryptographic communication system constituted by a first communication device, and a second communication device that stores a master key serving as an encryption key, the cryptographic communication system being characterized in that said first communication device has a common key storing unit configured to store a key pair constituted by a first key serving as a common key used to communicate with said second communication device and a second key obtained by encrypting said first key by using said master key held by said second communication device, and also has a common key transmitting unit configured to transmit said second key to said second communication device, and said second communication device has common key obtaining unit configured to receive said second key and obtaining said first key by decrypting said received second key by using said master key.