Cryptographic communication system, cryptographic communication device, cryptographic communication method, and cryptographic communication program

Abstract

According to one embodiment, a transmitting device includes an encryption key pre-fetching unit and an encryption chunk generation unit. The encryption key pre-fetching unit acquires the encryption key for encrypting plaintext data from a key management system before receiving the plaintext data. The encryption chunk generation unit generates a packet in which first encrypted data acquired by encrypting first plaintext data using a first encryption key and a first key ID of the first encryption key are stored, and a second key ID of a second encryption key used for encrypting second plaintext data transmitted after the first plaintext data, is embedded. A receiving device includes an encryption chunk analysis unit and a decryption key pre-fetching unit. The encryption chunk analysis unit analyzes the packet and reads the second key ID. The decryption key pre-fetching unit acquires the second encryption key corresponding to the second key ID read by the encryption chunk analysis unit from the key management system.