Speech scrambling with Hadamard transform in frequency domain
Yuan Wu, Boon Poh Ng · 2003
A speech scrambling algorithm is proposed in this paper based on Hadamard transform in frequency domain. It has a larger key space than the permutation algorithms. Simulations of this algorithm used in telephone communication were carried out. The results showed that this algorithm has low residual intelligibility and the recovered speech quality is fairly good. Fast algorithm is provided to reduce the computational cost.