Abstract: The pseudorandomness and complexity of binary sequences generated by typical Lorenz chaotic system and Chebyshev map are analyzed and discussed.The binary sequences are obtained from the chaotic real-valued sequences generated by chaotic systems by using T.Kohda binary quantification algorithm.The statistical test，correlation function，spectral analysis，Lempel-Ziv complexity and approximate entropy are regarded as quantitative measures to characterize the pseudorandomness and complexity of binary sequences.The experimental results show the finite binary sequences generated by chaotic system approach the random sequences of Lempel-Ziv level.They are of good properties in the pseudorandomness，complexity and nonperiodicity.However，their pseudorandomness and complexity do not enhance with the sequence length increased，but degrade in the criterion of approximate entropy.Furthermore，the results of data statistics analysis show that the Lorenz system is better than Chebyshev map as the source of pseudorandomness.

Key words: chaotic system, finite binary sequence, pseudorandomness of sequence, complexity of sequence

摘要： 分析和讨论了由经典的Lorenz混沌系统和Chebyshev映射所生成的二进制序列的伪随机性和复杂性，采用T.Kohda混沌二进制量化算法，将混沌系统所产生的实数序列转换为相应的二进制序列；从统计检验、自相关性、频谱、Lempel-Ziv复杂度和近似熵等多方面对序列的伪随机性和复杂性进行定量分析。统计分析结果表明对由混沌系统所产生的有限二进制序列逼近Lempel-Ziv意义的随机序列，它具有较高的伪随机性、复杂性和非周期性，但是序列的伪随机性和复杂性并不随序列长度的增加而提高，在近似熵评价指标中呈显出降低的趋势。同时，作为伪随机源，Lorenz混沌系统略比Chebyshev映射好。

关键词: 混沌系统, 有限二进制序列, 序列伪随机性, 序列复杂性