基于Radon变换与超混沌理论的图像加密方法研究

发布时间：2018-10-11 11:30

【摘要】：近年来,数字图像信息在网络传输过程中的安全已经成为了人们日益关注的焦点问题,而解决图像信息安全性最有效的技术就是图像加密技术,因此如何对图像进行加密显然已经成为了一个非常重要的研究课题。相比较于混沌而言,超混沌具有更加复杂的动力学特性和更加强的对系统控制参数以及初值的高度敏感性,所以将超混沌应用在数字图像加密中来,可以使图像的加密效果、密钥空间、安全性以及抗攻击性都会更好。本文充分采用了超混沌系统的优势,在Radon变换加密和超混沌理论的基础上,提出了一种基于Radon变换与超混沌相结合的加密方法,此方法在利用图像的Radon谱置乱的过程中引入超混沌系统,由此超混沌系统可以得到伪随机性更强的、呈现非周期状的和更加复杂的时间序列。将这些时间序列进行预处理后应用到本文的加密算法中,可以充分的加大密钥空间从而使加密的密钥变得更加安全。分析了一种仅仅使用Radon变换对图像进行加密的算法,无论是从视觉效果还是性能分析上,此方法的加密效果都没有引入超混沌后的加密方法的效果好。说明了将超混沌与Radon变换相结合是一个正确的选择。对本文算法进行了各种实验仿真与分析,在抗差分性分析时将本文算法的结果与一种仅用超混沌加密方法进行了对比,结果表明本文算法NPCR和UACI的值更加接近理想值。通过明文图像和密文图像的相关性、抗攻击性、灰度直方图以及密钥敏感性的分析也均证明本文算法的加密效果比较理想,从而说明了此算法具有一定的可行性、优越性、安全性和抗攻击性。
[Abstract]:In recent years, the security of digital image information in the process of network transmission has become the focus of increasing concern, and the most effective technology to solve the security of image information is image encryption technology. Therefore, how to encrypt images has become a very important research topic. Compared with chaos, hyperchaos has more complex dynamic characteristics and higher sensitivity to system control parameters and initial values, so the application of hyperchaos in digital image encryption can make the image encryption effect. Key space, security, and anti-attack are all better. Based on the theory of Radon transform encryption and hyperchaos, an encryption method based on the combination of Radon transform and hyperchaos is proposed in this paper. The hyperchaotic system is introduced in the process of scrambling the Radon spectrum of the image. Thus, the hyperchaotic system can obtain more pseudorandom, aperiodic and more complex time series. When these time series are preprocessed and applied to the encryption algorithm in this paper, the key space can be enlarged sufficiently to make the encrypted key more secure. This paper analyzes an algorithm which only uses Radon transform to encrypt the image. Whether from the visual effect or the performance analysis, the encryption effect of this method is not introduced into the hyperchaotic encryption method. The combination of hyperchaos and Radon transform is a correct choice. The simulation and analysis of this algorithm are carried out, and the results of this algorithm are compared with that of a hyperchaotic encryption method. The results show that the values of NPCR and UACI are closer to the ideal value. By analyzing the correlation between plaintext image and ciphertext image, anti-attack, gray histogram and key sensitivity, it is proved that the encryption effect of this algorithm is satisfactory, which shows that this algorithm has certain feasibility and superiority. Safety and anti-aggression.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O415.5;TP309.7;TP391.41

【相似文献】