Audio and optical cryptography

Abstract

In visual cryptography the additive property of light is used. Also the shares are random and therefore suspect to a censor. In this paper we present two new cryptographic schemes which use music and the wave properties of light. Both schemes are also secret sharing schemes in which shares are music or images and are not suspect to a human censor. Our scheme guarantees perfect privacy as well as high quality. To decrypt the message, one just plays two shares on a stereo system. There are two decryption methods which are either based on the interference property of sound or based on the stereo perception of the human hearing system. In optical cryptography, we use pictures as covers and the wave interference property of light. The privacy is perfect and the modiéd images are non-suspicious. The Mach-Zehnder interferometer is used as the decryption machine.