Secure Hybrid Spread Spectrum System for Steganography in Auditive Media

Steganography is used to embed secret messages in cover media. This is especially important in areas, where the use of cryptography is prohibited. In this paper, we introduce a novel hybrid steganographic algorithm for digital audio data. We enhance a direct sequence spread spectrum (DSSS) system with aspects of frequency hopping to vary the carrier frequency of the binary phase shift keying (BPSK) signal, representing the secret message. Further, we adopt the number of chips per secret bit. These modifications give a more secure steganographic system, making guesses about the bit-rate or message length less feasible. Further, an adaptive amplitude control is used to guarantee inaudibility, even in silent passages. After an overview of the DSSS technique, we highlight our contributions to form a more secure steganographic system. The results from our working prototype are pointed out and further usage scenarios in relation to future research are given.