One-Dimensional Audio Scrambling based on Cellular Automata

Abdel Latif Abu Dalhoum

doi:10.5539/mas.v13n1p136

Abstract

Digital audio scrambling is a process used in audio security applications. Scrambling of audio files breaks the correlation between adjacent samples in order to convert the original audio to an unintelligible format. Scrambling is used to protect the audio against wiretapping and illegal surveillance, in addition to being a step in security algorithms, such as watermarking and encryption algorithms. Cellular automata are models that are discrete in nature and depend on simple and local rules to achieve an interesting overall behavior. Two-dimensional cellular automata were previously proposed as a key generation mechanism to scramble audio files. The mechanism was built upon be researchers in the multimedia security field. This paper explores the use of one-dimensional cellular automata in audio scrambling, which simplifies the process as deploying two-dimensional cellular automata requires changing the dimension of the audio file and the one-dimensional cellular automata does not, additionally, elementary one-dimensional cellular automata requires less parameters to configure. The scrambling degree is used to evaluate the model effectiveness in breaking the correlation of adjacent samples. In the experiments, different parameters are taken into account including the cellular automata class, the iterations needed and the method used to calculate the cells at the boundary. Experiments show that the one-dimensional cellular automata are capable of scrambling the audio file without any dimensional change and the chaotic rules tested give the highest scrambling degree.

Highlights

Scrambling techniques were used to hide analog audio in transmission, for example, scrambling techniques were used in cable TV broadcast to protect copyrights and in transferring images from satellites to ground stations, in addition to military communications (Yan, Fu, & Kankanhalli, Progressive Audio Scrambling in Compressed Domain, 2008)
This paper proposes the use of Elementary one-dimensional Cellular Automata in Audio Scrambling (ECAAS)
In (Li & Qin, Audio Scrambling Algorithm Based on Variable Dimension Space, 2009) the output might need padding, and the whole algorithm is dependent on the idea that changing the dimension will result in better scrambling, but in the algorithm proposed here we show that there is no or little benefit from changing the dimension in schemes dependent on cellular automata since the simplest CA are capable of scrambling the audio effectively

Summary

Introduction

Scrambling techniques were used to hide analog audio in transmission, for example, scrambling techniques were used in cable TV broadcast to protect copyrights and in transferring images from satellites to ground stations, in addition to military communications (Yan, Fu, & Kankanhalli, Progressive Audio Scrambling in Compressed Domain, 2008). Scrambling can be used alone, in applications such as copyright protection (Yan, Fu, & Kankanhalli, Progressive Audio Scrambling in Compressed Domain, 2008) (Fu, Yan, & Kankanhalli, 2005) and to protect from illegal Surveillance and wiretapping (Augustine, George, & Deepthi, Sparse representation based audio scrambling using cellular automata, 2014). The scrambling can be used as a pre-process to audio watermarking algorithms (Li, Qin, & Shao, Audio Watermarking Pre-process Algorithm, 2009) (Hiary, Abu Dalhoum, Madain, Ortega, & Alfonseca, 2016)

Results

Discussion

Conclusion