Abstract
This paper presents an image encryption algorithm for secure transmission over public network. The proposed scheme is based on the hybrid concept of DNA computing, 3D chaotic system and the SHA-256 hash function. SHA-256 is utilized to initialize a chaotic system, producing a pseudorandom key stream. Additionally, a secret key is divided into sub-keys, which are combined with the chaotic key stream through XOR operations. The resulting binary data undergoes permutation for enhanced security and is subsequently encoded using DNA rules, leveraging the vast combinatorial potential of DNA sequences. Finally, the DNA-encoded data is translated back into a binary format to produce the cipher image. The technique is highly sensitive to the initial conditions of the chaotic system and demonstrates high randomness. The result of this experiment shows that the encryption technique offers strong security by comparing the histogram, chi-square test, correlation, and information entropy.