Hybrid Audio Steganography and Cryptography Method Based on High Least Significant Bit (LSB) Layers and One-Time Pad—A Novel Approach

摘要

The paper proposes a novel chaos based audio steganography and cryptography method. It is a higher Least Significant Bit (LSB) layers algorithm in which the secret message is encrypted first by one-time pad algorithm. Two chaotic sequences of Piecewise Linear Chaotic Map (PWLCM) were used. In the encryption process, the key for one-time pad is generated by PWLCM chaotic map. In the steganography process, the second sequence of PWLCM is used to generate a random sequence. Then, indices of the ordered generated sequence were used to embed the encrypted message in randomly selected audio samples. The encrypted data were embedded on the higher layers other than the LSB using efficient bits adjustment algorithm, in order to increase the robustness against noise addition or MPEG compression. An analysis is discussed for the proposed scheme. For the steganography algorithm, the proposed scheme overcomes the main two problems for LSB coding, which are the low robustness of secret message extraction and destruction. For the former, the proposed method encrypts the secret message by perfect efficient algorithm which is the one-time pad. Regard of the second one, the secret message is hidden in higher layers which improve the robustness against signal processing manipulation. The main three steganography characteristics were tested and evaluated which are high capacity, perceptual transparency and robustness. Furthermore, the drawbacks of key generation and key distribution for one-time pad is sloved by using the chaotic maps. For the experimental results, waveform analysis and signal-to-noise Ratio are made, which show the high quality of the stego audio, and hence demonstrate the efficiency of the proposed scheme.