Enhancing Security and Randomness of DNA Cryptosystem Generated by Using Mealy Machine

In the current digital landscape, data security is paramount due to the increasing threats posed by hackers.The Deoxyribonucleic Acid (DNA) cryptosystem offers a secure method of data transmission by converting plaintext (PT) into ciphertext (CT) using a DNA encoding table.This paper proposes a novel DNA cryptographic technique that integrates a randomly generated Mealy machine with DNA encoding to bolster security.Initially, a 256-bit secret key is generated based on the receiver's credentials.Detailed explanations of key generation, encryption, and decryption processes are provided, along with illustrative examples.Extensive testing, including frequency distribution, resistance to security attacks, and comparative analysis, affirms the effectiveness of this model.Additionally, the randomness of the CT is validated by the National Institute of Standards and Technology (NIST) test suite, which yields an average p-value of 0.72, surpassing existing schemes.Furthermore, the system achieves an average avalanche effect of 79%, ensuring robust security.These results demonstrate the superior security and performance of the proposed cryptosystem compared to existing DNA-based techniques.