US Patent 7773746 Encryption system, encryption device, decryption device, program, and integrated circuit

An encrypted communication system, capable of performing processing with the speed higher than the conventionally achieved speed, includes an encryption device and a decryption device sharing parameters that satisfy p=3 and q=2^k (k: an integer of 2 or greater). The decryption device generates a public key and a private key using the parameters, the encryption device encrypts a plain text using the public key, and then, the decryption device decrypts the encrypted text using its own private key.