A technique for securing digital audio files based on rotation and XOR operations

Security of digital audio files is the need of the hour. In this context, researchers have proposed several techniques for the secure communication of audio files. But unfortunately, these are vulnerable to differential attack. So, we propose a WORD-oriented technique for securing digital audio files based on rotation and XOR operations. The key concepts of the designed encryption algorithm are the RX (Rotation-XOR) operations, i.e., the plain audio samples are first left-rotated by the sum-of-digits of the previous audio samples, and then XOR-ed with the previous audio samples. The designed encryption algorithm encodes a digital audio file into a random (noise-like) audio file. Several encryption and decryption evaluation metrics, such as Adjacent Sample Correlation Coefficient (ASCC), Crest Factor (CF), Number of sample Change Rate (NSCR), Mean Square Error (MSE), Peak Signal-to-Noise Ratio (PSNR), etc., are applied on several digital audio files of varying sizes, to empirically assess the performance and efficiency of the proposed technique. The results of these metrics show that the cipher audio files have a very high key sensitivity, ideal ASCC, ideal CF, 100% NSCR score, zero MSE, and infinite PSNR. Moreover, the technique strongly resists the brute-force attack, differential attack, and other statistical attacks.