中文摘要：

针对语音加密算法A5寄存器级数过短并且抗穷举攻击能力弱的特点,提出了一种简单的自同步序列密码,用于对大数据量语音信号的加密传输.短的种子密钥不能完全初始化寄存器,为了达到扩展成足够长的初始密钥的目的,设计了一种结构简单并且非线性度很高的密钥扩展算法.利用此算法可以获得随机性强的初始密钥序列.利用延时器测试算法的加密效率,证明了此算法能够安全地使用在语音加密中.

英文摘要：

The register series of voice encryption algorithm A5 are too short,and its resistance to brute-force attack is weak.So a simple self-synchronizing stream cipher is proposed for encrypting large amounts of voice data and the transmission.In order to generate the long initial key from the short seed key,which is used to initialize the register of self-synchronization,a simple but very high nonlinear key expansion algorithm is designed.A strong random initial key sequence can be obtained by using the algorithm proposed.Then,a delayer is used to test the efficiency of encryption algorithms.It proves that the algorithms can be used in voice encryption safely.