为了提高现有混沌保密通信系统的加解密速度和安全性,提出了一种新的即时同步流密码数字保密通信方案,在该方案中利用改进元胞自动机进行加密,并采用扩展密钥技术和置乱技术.数值模拟结果表明:该方案能产生随机性很好的流密码,并且具有较高的加解密速度和非常高的抗破译能力. In order to improve the encryption and decryption speed and security of the existing chaotic secure communication system, a new digital secure communication scheme for instantaneous stream cipher is proposed. In this scheme, Cellular Automata (CA) And scrambling technology.The numerical simulation results show that the proposed scheme can generate stream ciphers with good randomness and has high encryption and decryption speed and very high anti-deciphering ability.