中文摘要：

分组密码是一类广泛使用的加密方法.在网络数据加密体系中,为提高信息的安全性,需要保证初始密钥具有足够大的密钥空间.为克服量子计算机对短密钥的威胁,一种基于混沌映射的新型密钥扩展算法被提出.该算法将混沌映射融入到原SM4密钥扩展算法中,有效增大了密钥空间,提高了破译难度.

英文摘要：

Block cipher is a widely used encryption method. In order to improve the security of information in the network data encryption systems, the initial key should be guaranteed to be large enough. In order to overcome the threat of quantum computer to short initial keys, a key scheme based on chaotic map is proposed. The chaotic map is introduced into the original SM4 key scheme, which effectively increases the initial key space and greatly improves the resistance to key scheme attacks.Due to the limited logic resources in hardware implementation, a logistic map is chosen as a chaotic system in this paper. Although the logistic map has many excellent properties of chaotic system, such as initial value sensitivity,randomness, ergodic, etc, there are still a lot of problems that we need to pay attention to. The parameter μ is the system parameter in the logistic map. The value of μ controls chaotic characteristics in the logistic map. When μ is equal to 4, the dynamic characteristics of logistic map are best. The values of data transmitted in the network are all quantified as 0 and 1. In order to implement the logistic map in a digital circuit, the digital quantization is needed.The bit sequence design quantization is very simple and saves resource consumption. Compared with other quantization methods, bit sequence design quantization can be implemented in hardware parallelly. United States National Institute of Standards and Technology launched the test program package to test the random numbers. The test program package includes frequency detection, block frequency detection, run test, etc. Those tests are used to detect the randomness in binary sequence of arbitrary length. The test program package proves that the sequence generated by the logistic map has a great randomness characteristic. After the security analysis of logistic map, the hardware implementation of logistic map is carried out in this paper. Based on the theoretical analysis and hardware implementation in the logistic map, a new SM4 key scheme co