Color Image Encryption Method Based on DNA Strand Displacement Analog Circuit

A color image encryption method based on a DNA strand displacement analog circuit, which essentially combines a DNA strand displacement technology with an image chaotic encryption method by utilizing the compilability of a DNA strand sequence, and the method comprises the following specific steps:

• step 1:
• determining an idealized reaction network that can describe a Rössler chaotic system;
• step 2:
• determining an idealized reaction module and a DNA strand displacement reaction module corresponding thereto according to an idealized reaction equation;
• step 3:
• constructing a DNA strand displacement analog circuit according to the idealized reaction network and the reaction module;
• step 4:
• adopting an encryption method, and the detailed steps (1)-(5) of the encryption method are as follows:
• (1) generating a secret key by using the plaintext image;
• (2) setting the measurement accuracy of the concentration of a DNA strand as 0.1 nM, wherein the measurement is performed every 3 seconds;
• (3) extending the measured data to obtain a new chaotic sequence;
• (4) scrambling the color plaintext image at the level of the three components of R, G, B in consideration of the relation between the three components of R, G, B in a color image;
• (5) performing scrambling at a pixel level by utilizing the extended chaotic sequence;
• (6) generating a scrambling sequence U by using the chaotic sequence;
• (7) generating a scrambling sequence V by using the chaotic sequence;
• and
• (8) performing diffusion processing on the scrambled image;
• step 5:
• adopting a decryption method, which comprises:
• removing the diffusion effect on the encrypted image according to the inverse process of the encryption method to obtain a plaintext image;