New Audio Secret Sharing schemes with time division technique

An Audio Secret Sharing (ASS) scheme is a special type of secret sharing scheme [3], which the shares of embedded messages use music as cover sound. Desmedt et al. firstly introduced the (2, 2) ASS scheme with one cover sound and also the generalized (2, n) ASS scheme with [log(2)n] different cover sounds. No only will more cover sounds overburden the human hearing system but also may become difficult for people to distinguish the secret bit correctly. Thus, their scheme is not practical when n is large. In this paper, we will propose two new (2, n) ASS schemes, which carefully employ the technique of time division with only one cover sound. Comparing with the first scheme, the second scheme has the advantage of flexible improvement in relative contrast as needed. To test the acoustic result, we implemented these two proposed (2, n) ASS schemes for small n using one wave-type cover sound and then obtained near expected results.