A new speech scrambling concept based on Hadamard matrices
V. Šenk, Vlado Delić, Vladimir Milošević · IEEE Signal Processing Letters · 1997
The principles of a new speech scrambling concept are presented, whereby the speech components are linearly combined in contrast to their conventional permutation. A computationally and cryptographically efficient solution based on Hadamard matrices is proposed and its advantages shown. The idea is general and easily applies to all existing speech scramblers providing for both lower residual intelligibility and greater cryptanalytic efforts, maintaining the bandwidth and the speech quality.