Improvements on Audio and Optical Cryptography

Audio and optical cryptography schemes in [1] are secret sharing schemes that protect audio and visual secrets by using sounds and images, respectively. However, 2-out-of-n schemes in [1] are constructed by log 2 n independent 2-out-of-2 schemes, meaning so that a 2-out-of-n scheme needs log 2 n different cover sounds or images. More cover sounds (images) will be more difficult for the human hearing(vision) system to hear(see) the secret. In this paper new constructions for the 2-out-of-n audio and optical secret sharing schemes are proposed. Our schemes only need one cover sound or image.