Audio Scrambling Algorithm Based on Variable Dimension Space

To solve the problem that the combination of encrypting parameters is too less in one-dimensional linear congruence mapping and the poor security in encryption, an audio scrambling algorithm based on variable dimension space (ASVDS) is presented. When implemented in audio position space, our algorithm changes the dimension of coordinates and uses arbitrary matrices to scramble audio, which has following advantages: (1) variable dimension operation in multi-scale space increases the combination of encrypting parameters which increases the difficulty being attacked; (2) in our scrambling method, random generated high dimensional transform matrix has no fixed period and has no special restriction on the audio length which enhance the security to compare with conventional audio scrambling transform method; (3) using the random generated high dimensional matrix, the method has a wonderful one time scrambling performance whilst the scrambling cost is low; (4) the method use the inverse matrix to recover the scrambled audio in real time, resulting in a low recovering cost. Experiments show the validity of our proposed algorithm in audio scrambling, low cost in recovering the scrambled audio and also a wonderful one time scrambling performance. The algorithm presented here is robust in enduring common attacks, such as Gaussian noise addition, data loss, data amplification and data reduction.