The characteristics of digital audio such as a large quantity of data, strong correlation and high redundancy, make it difficult to meet real-time security to encrypt digital audio by using conventional encryption algorithms. An audio cryptography scheme based on binary audio is proposed by using the auditory properties of human being. In order to reduce the amount of audio data, the secret audio is transformed into binary audio by halftone as in the image process. The basic array of (k, n) threshold in visual cryptography scheme is used to share the binary audio so that correlations in audio data is removed. The secret audio information can be directly decrypted through human auditory system by synchronously playing any k shares of the binary audio, but synchronously playing any m(m展开▼