LAUSR

Many plaintext-related or non-plaintext-related image encryption algorithms based on chaotic systems have been found inefficient and insecure under chosen plaintext attacks. In this paper, a novel plaintext-related mechanism based on the peculiarity of plaintext DNA coding (PPDC) is presented and used to developed a symmetric image encryption algorithm. In our scheme, a hyper-chaotic Lorenz system is used to produce four chaotic sequences. Firstly, by using one chaotic sequence to control the DNA rules, the original image is encoded to obtain the image DNA coding and PPDC, and another chaotic sequence is encoded into a DNA sequence, which is used in the DNA XOR operation. Then, the processing of the remaining two chaotic sequences by using the PPDC is performed to obtain two key streams, which are used in the permutation stage. After performing the traditional permutation operation and DNA XOR operation, the cipher image is obtained. Because of the use of the PPDC, the key streams used in the permutation stage are related to the secret keys and plaintext image, which gives the encryption system higher plaintext sensitivity and security. The simulation experimental results and security analysis demonstrate that the proposed encryption system possesses high efficiency and security and can resist various typical attacks like exhaustive attack, statistical attack, and differential attack effectively.