Abstract: The paper presents the general encryption approach. To address the synchronization problem of the voice communication, it uses the filter banks that can analysze and synthesize the voice. And it improves the algorithm proposed by Lee Shanlin. The approach not only reduces the computation cost but also deducts the redundancy data. Moreover, its effect is better than the algorithm proposed by Lee Shanlin as the result of software simulation.

Key words: Filter banks, Encryption, Asynchronization

摘要： 给出了加密的一般模型，为了解决非同步语音加密的问题，用滤波带分析语音的分解和合成，对李善林提出的同步加密算法进行改进，在语音数据帧不引入冗余数据的情况下，实现非同步加密，相对于李的算法降低了运算开销，在同等条件下，一次性加密算法的时间开销只有原来的20%左右，同时恢复语音效果更好。

关键词: 滤波带, 加密, 非同步