一种基于SPIHT编码过程的图像选择加密算法  

Selective Encryption Scheme of Compressed Images Based on SPIHT Coding Computer Engineering and Applications

作　　者：董贤会[1] 石锐[1] 余晨韵[1] 

机构地区：[1]重庆大学计算机学院,重庆400044

出　　处：《世界科技研究与发展》2013年第5期627-632,640,共7页World Sci-Tech R&D

基　　金：科技部科研院所技术开发研究专项(2012EG137242)资助

摘　　要：在深入研究多级树集合分裂编码(SPIHT)的基础上提出了一种安全高效的图像加密算法。首先,重点分析了SPIHT的码流结构以及各部分数据对解码的影响,确定了重要数据并对其进行加密。其次,改变加密层数K控制加密强度,从而进一步提高了加密效率。最后,在对LIS扫描过程中引入了混乱机制,降低了码流相关性,使得算法更加安全。实验表明:该算法安全性高,加密速度快,仅需加密原图数据量的2.3%左右便可以达到很好的加密效果,满足格式兼容性要求并且能够适应网络实时传输。A safe and effective encryption scheme for image is proposed by utilizing set partitioning in hierarchical trees （ SPIHT）. At first, the compressed data of SPIHT is analyzed to find the function of.different data for decoding so that the important data can be chose for encoding. To further enhance the encryption efficiency, encryption intensity is controlled by changing encryption layer. In addition, confusion mechanism is used during LIS scanning process, thus reducing streaming correlation and making algorithm safer. Theoretical analysis and numerical simu- lations show that the encryption performance is good by only encrypting around 2.3 percent of original image. The compatibility is main- tained, satisfying the demanding for real-time processing.

关 键 词：图像压缩 SPIHT编码 选择加密 小波变换 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]