Speech encryption using finite precision chaotic maps based stream ciphers

Efficient and simple design of speech encryption-based stream cipher is produced and suggested in this paper with name finite precision chaotic map-based stream cipher (FPCM-SC) system. Two pseudo random bits generator (PRBG) are built by hybrid chaotic maps using finite precision format and named finite precision chaotic XOR based PRBG (FPCXOR-BRPB) and finite precision chaotic hopping based PRBG(FPCH-PRBG). The statistical security analysis and speech residual unintelligibility measures are presented for the two proposed systems. The results show that key space for FPCXOR-PRBG is 214*32 and for FPCH-PRBG is 216*32 that are large enough to resist against all kind of brute force attack. Also, residual unintelligibility measures show that the speech signal is unintelligible signal and can't be listen by an attacker.