中图分类号：TP309 文献标志码：A DOI: 10.16157/j.issn.0258-7998.222975 中文引用格式： 庞宇，魏东，王俊超. 基于混沌浮点运算的医学图像加密方法与FPGA实现[J]. 电子技术应用，2023，49(1)：135-140. 英文引用格式： Pang Yu，Wei Dong，Wang Junchao. A medical image encryption method based on chaos floating-point operation and its realization by FPGA[J]. Application of Electronic Technique，2023，49(1)：135-140.
A medical image encryption method based on chaos floating-point operation and its realization by FPGA
Pang Yu1，Wei Dong1，Wang Junchao2
1.Photoelectronic Information Sensing and Transmission Technology Laboratory，Chongqing University of Posts and Telecommunications，Chongqing 400065，China；2.School of Microelectronics and Communication Engineering，Chongqing University，Chongqing 400044，China)
Abstract： Aiming at the high confidentiality requirement of medical image data transmission in the Internet, an encryption method based on Logistic chaotic floating point number operation is proposed for medical image encryption. In this encryption method, PRNG based on Logistic chaos was designed with double-precision floating-point operations and described by the Verilog . The comprehensive design of encryption method is realized on the development platform of Cyclone IV series DE2-115 of Altera Corporation. The security of encryption algorithm is analyzed from the cryptographic perspectives such as key sensitivity test, histogram analysis, correlation test, information entropy processing, etc. By comparing with some existing image encryption algorithms, it is found that the image encrypted by this encryption algorithm has the characteristics of being sensitive to keys, small correlation coefficient and high information entropy. In addition, the FPGA-based hardware encryption system has high encryption stability and good real-time performance.
Key words : image encryption；chaos map；floating point arithmetic；PRNG；FPGA
基于混沌算法的伪随机数生成器（Pseudo Random Number Generator , PRNG）生成的伪随机序列对初始值极度敏感、周期长、密钥空间大，与其他数据序列相比在安全性上具有明显的优势，用于医学图像加密具有很可观的加密效果。除了算法严格性外，一种有效的加密系统实现技术可保证加密的速度得到提升。而硬件实现的方式在能够满足应用实时性的同时又可以防止运行算法的攻击。现场可编程逻辑器件（Field -Programmable Gate Array ，FPGA）以其高并行、可定制、能重构、低成本等特点十分适合于混沌加密算法的硬件实现。