CAJ | 학술논문

针对当前的灰度图像加密存在运算效率低以及有损图像性质等不足，设计了像素混合机制，提出基于扩散替代的灰度图像加密算法。首先利用像素混合机制预处理图像；再将混合图像分割成相关密钥的动态分块，基于所设计的置乱规则，对混合图像分块置乱；再由所设计的替代结构，对置乱分块进行加密；重组密文块，输出密文。该灰度图像加密算法显著避免了当前加密算法依赖多系统参数带来的严重时耗难题并保证了解密图像质量。最后在MATLAB仿真平台上测试该算法，结果显示：与当前加密机制对比，该算法具有接近的安全性能，且运算效率更高，解密质量更好。
침대당전적회도도상가밀존재운산효솔저이급유손도상성질등불족，설계료상소혼합궤제，제출기우확산체대적회도도상가밀산법。수선이용상소혼합궤제예처리도상；재장혼합도상분할성상관밀약적동태분괴，기우소설계적치란규칙，대혼합도상분괴치란；재유소설계적체대결구，대치란분괴진행가밀；중조밀문괴，수출밀문。해회도도상가밀산법현저피면료당전가밀산법의뢰다계통삼수대래적엄중시모난제병보증료해밀도상질량。최후재MATLAB방진평태상측시해산법，결과현시：여당전가밀궤제대비，해산법구유접근적안전성능，차운산효솔경고，해밀질량경호。
Aiming at the deficiencies of current greyscale image encryption in low operation efficiency and the nature of image lossy, we designed the pixels mixing mechanism and presented the diffusion substitution-based greyscale image encryption algorithm.First it employs pixels mixing mechanism to preprocess the image, and then divides the mixed image into dynamic blocks of the related keys, and scrambles the mixed image blocks based on the scrambling rule designed in the paper; The next step is to encrypt the scrambled blocks with the substitution structure designed in the paper;Then the ciphertext blocks will be reconstructed and the ciphertext will be sent out.The greyscale image encryption algorithm proposed in this paper clearly prevent the problem of sever time-consuming brought by current encryption algorithm relying on multiple system parameters; and guarantees the quality of decrypted image.Finally we tested the proposed algorithm on Matlab simulation platform, result showed that compared with current encryption mechanism, the proposed algorithm has very close security performance, but its operation efficiency is higher and the decryption quality is better as well.