A cryptographic system based upon the continued fraction

The authors propose a cryptographic system in which the sender and the receiver hold the same secret key. The system is a one-key system while the RSA system is a public-key system in which the enciphering key and the deciphering key are not identical. The encoding function in the proposed system is based on a linear equation with two variables. The processes of encoding and decoding are simple in this system. The operations in the system include multiplication and addition only, thus making efficient ciphering possible.<>