Abstract: The domains of the quantized coefficients are variable in sub blocks during the image compressing process. The usual methods such as exclusive or can not be used to encrypt them. So the article proposes a chaotic-sequences-based and modular-addition-liked method to encrypt the quantized coefficients. By using the cipher-feedback mode, the algorithm can resist the known-plaintext attacks and chosen-plaintext attacks. Experimental result shows the algorithm is effective.

Key words: chaos, image encryption, modular addition

摘要： 在图像压缩过程中，子块中的DCT系数经过量化后，取值区间是各不相同的，不能采用通常的诸如异或运算等方式实现加密。文章提出一种基于混沌序列的、类似模加运算的方法来对量化系数进行加密。并通过运用密码反馈机制，使算法能够抵御已知明文攻击和选择明文攻击。实验结果表明该算法是有效的。

关键词: 混沌, 图像加密, 模加

CLC Number: 

• TP301.6