A Novel Image Encryption Algorithm Based on DNA Subsequence Operation

Algorithm 1

An image encryption algorithm based on DNA subsequence operation.

Input: An 8-bit image 𝐴 and chaotic parameters (𝑥₀,𝜇₁,𝛾₁,𝑦₀,,𝜇₂,𝛾₂)

Output: The encrypted image 𝐵

(1) [𝑆₁,𝑆₂,𝑆₃,𝑆₄]∶= four DNA sequences obtained from image 𝐴;

(2) [𝑃₁,𝑃₂,𝑃₃,𝑃₄]∶= four groups of DNA subsequences obtained from image [𝑆₁,𝑆₂,𝑆₃,𝑆₄];

(3) [𝑥₁,𝑢₁,𝑦₁,𝑢₂,𝑧₁,𝑢₃,𝑞₁,𝑢₄]∶= eight chaotic parameters obtained by 2D Logistic map under chaotic initial parameters (𝑥₀,𝜇₁,𝛾₁,𝑦₀,,𝜇₂,𝛾₂);

(4)  [𝑋,𝑌,𝑍,𝑄]∶= four chaotic sequences obtained by Logistic map under the chaotic parameters (𝑥₁,𝑢₁,𝑦₁,𝑢₂,𝑧₁,𝑢₃,𝑞₁,𝑢₄);

(5)  𝐴₁=𝐷𝑒𝑙𝑒𝑡𝑖𝑜𝑛(𝑃₁,𝑋);

(6)  𝐴₂=𝐷𝑒𝑙𝑒𝑡𝑖𝑜𝑛(𝑃₂,𝑌);

(7)  [𝐸₁,𝐸₂]=𝐸𝑙𝑜𝑛𝑔𝑎𝑡𝑖𝑜𝑛−𝑡𝑟𝑢𝑛𝑐𝑎𝑡𝑖𝑜𝑛(𝐴₁,𝐴₂);

(8) 𝐴₃=𝐷𝑒𝑙𝑒𝑡𝑖𝑜𝑛(𝑃₃,𝑍);

(9) 𝐴^′₃= Transformation (𝐴₃,𝑍);

(10)  𝐴₄=𝐷𝑒𝑙𝑒𝑡𝑖𝑜𝑛(𝑃₄,𝑄);

(11)  𝐴^′₄= Transformation (𝐴₄,𝑄);

(12)  [𝐵₁,𝐵₂,𝐵₃,𝐵₄]=𝑅𝑒𝑐𝑜𝑚𝑏𝑖𝑛𝑒−𝑠𝑢𝑏𝑠𝑒𝑞𝑒𝑛𝑐𝑒(𝐸₁,𝐸₂,𝐴^′₃,𝐴^′₄);

(13)  [𝐵^′₁,𝐵^′₂,𝐵^′₃,𝐵^′₄]=𝐶𝑜𝑚𝑝𝑙𝑒𝑚𝑒𝑛𝑡(𝐵₁,𝐵₂,𝐵₃,𝐵₄);

(14)  𝐵∶= carry out DNA decoding and recombining binary bitplanes for 𝐵^′₁,𝐵^′₂,𝐵^′₃,𝐵^′₄;