混沌系统的图像加密

提出了一种基于级联混沌系统的图像加密算法。实验结果表明，这种加密算法具有高度的安全性和有效性。关键词： 图像加密算法；混沌；级联混沌 目前混沌加密己成为密码学研究的热点之一，但已有的大部分混沌加密算法都是基于单个混沌系统的。事实表明，一些混沌映射可通过相空间重构的方法精确预测出来[1]。另外，由于计算机精度的限制，单混沌系统输出的时间序列并不能达到理论上的完全随机，而可通过多个混沌系统的级联使1382002GDCTK LP(M/K)(NIL). PS DCT(M/K)(N/L)],i=h,j=G[0,1GSm=88(k=1,2,,M/8Sign(nn)ⅠB.IBIlByDCT2,,M/K,j=1,2,,N/L),IB=j+(-1)(N[O,1,,31L). IPⅠP3.3K L)SteplIBi= pImmage3.2.3Outl mageInl mageStep2.(1k(k=1,Out/ mageyhSkm DCtep2.(1)rk yk(= 1,g km10.88 DCTJPE GPGDCTIPEJPEG3.2.43.3JPEGMPEG, JPEGx0=0.60773).2en aDCTx0=0.60773)Huffman[2,8]JPEG1d.2d0=0.60772SG3DCT3a,3b3 cJPEG90DCTDCTa Lena原图b加密图像c解密恢复的图像d密钥错误解密的图像1994-2012 China academic journ图Hlec图像筐國咖密解密铺果. All rights reserved.htt:ww. cnkinet139B enn原图b加密图像c解密恢复的图像d密钥错误解密的图像图2图像域加密与解密结果a随机噪声b均匀噪声C JPEG压缩图3加密图像的失真对解密图像的影响[4] C Shi, B Bhargava. Light -w eight M PEG video encr yption agorithm Al. In: Pr oc ee dings of the Int ernat ional ConferenceDelhi, India, 1998. 55 6[5 Josef Scharinger. Fast en cry pt ion of image dat a usin g ch aot iKolm og or ov flows[A]. In: Proceedings of E lectronicImaging 97, Security and Watermarking of Multimed ia Conten ts, S an Jos e,1997,3022:278289[6 Qi Don gxu, Zou Jiancheng. et al. New scramble tr ans form a-tion and applic at ion in inform at ion hiding[ J]. Ch inese Science(E),20,030(5):440447( in chinese)E),2000,30(5):440447)[1 Li Y uh uan. Comb inat orial Mathem at ics[ M I. Beijing: Beijing [7] Hui Xiang, et aL. D igital water ark ing sys tems w ith ch icNormal College press, 1998( in Chinese)sequences[ A]. In: Proceedings of Electronic Imaging99, Se-M,1998)cu rity and Waterm ark ing of Multimedia Contents, SPIE, San[2] Wu M insh eng, Wang Jiesheng. L iu Shen quan. Perm ut at ionJose,1999,3657:449457transformation of image[ J]. Chinese Journal of Computers, [8] Yi Kaixiang, Sun Xin, Shi jiaoy ing. Chaotic sequences bas ed1998,21(6):514519 in chines e)image encry pt ion alg or ith m[ J]. Journ al of Computer-A idedDes ign Com puler Graph ics, 2000, 12(9):672 676(in Chi-1998,21(6):514519leseWei, Qi Don gxu. Digit al image tran format ion and in-format ion hiding and dis guisin g techn ology[ J]. Chin ese Jour2000,12(9):672nal of Computers, 1998, 21(9):838 843( in Chinese676)1998,21(9):838843)o1994-2012ChinaAcademicJournalElectronicPublishingHouse.Allrightsreservedhttp://www.cnki.net