Abstract: Using the Devaney chaos theory，designd a compound chaos mapping as the encryption function，and have proven that the track is non-periodic for the initial value of finite decimal.It designs an encryption algorithm successively according to this，and realizes the encryption for sound documents.Afterward the simulation experiment has been carried on，it realized the key sensitivity analysis，the statistical analysis，as well as the correlation analysis of definite text and secret text.The experimental result proves that this system has the good cryptology performance，produces the large key space，meanwhile，it has good avalanche effect，resists exhaustion and the statistical analysis effectively.

摘要： 利用Devaney的混沌理论，设计了一个复合混沌映射作为加密函数，并证明了对于有限小数的初值，其轨道是非周期性的。依此设计了一个加密算法，实现了对语音文件的加密。随后进行了仿真实验，并对结果进行了密钥敏感性分析、统计分析和明文密文的相关性分析。实验结果证明该体系具有良好的密码学性能，产生的密钥空间大，并且该密钥有很好的雪崩效应，能有效地抵御穷举和统计分析。