Nowadays, the amount of data produced and stored in computing devices is increasing at an alarming rate. Tremendous amounts of critical and sensitive data are transmitted between all these devices. Thus, it is very imperative to guarantee the security of all these indispensable data. Cryptography is a commonly used technique to ensure data security. The fundamental objective of cryptography is to transmit data from the sender to the receiver in the most secure way, so that an attacker is unable to extract the original data content. This paper proposes a novel cryptosystem based on Deoxyribonucleic Acid (DNA) cryptography and finite automata theory. The system is made of three entities, namely a key pair generator, a sender and a receiver. The sender generates a 256-bit DNA based secret key based on the attributes of the receiver, and this key is used for data encryption. Then, a randomly generated Mealy machine is used for coding the DNA sequence, which makes the ciphertext more secure. The proposed scheme can protect the system against numerous security attacks, such as brute force attack, known plaintext attack, differential cryptanalysis attack, cipher text only attack, man-in-the-middle attack and phishing attack. The results and discussions show that the proposed scheme is efficient and secure than the existing schemes.

如今，计算设备中产生和存储的数据量正以惊人的速度增长。在所有这些设备之间传输了大量的关键和敏感数据。因此，必须确保所有这些必不可少的数据的安全性。密码术是确保数据安全的常用技术。加密的基本目标是以最安全的方式将数据从发送方传输到接收方，从而使攻击者无法提取原始数据内容。本文提出了一种基于脱氧核糖核酸（DNA）密码学和有限自动机理论的新型密码系统。该系统由三个实体组成，即密钥对生成器，发送者和接收者。发送方根据接收方的属性生成一个基于256位DNA的密钥，该密钥用于数据加密。然后，使用随机生成的Mealy机器对DNA序列进行编码，从而使密文更加安全。提出的方案可以保护系统免受多种安全攻击，例如蛮力攻击，已知的纯文本攻击，差分密码分析攻击，仅密文攻击，中间人攻击和网络钓鱼攻击。结果和讨论表明，所提出的方案比现有方案更为有效和安全。中间人攻击和网络钓鱼攻击。结果和讨论表明，所提出的方案比现有方案更为有效和安全。中间人攻击和网络钓鱼攻击。结果和讨论表明，所提出的方案比现有方案更为有效和安全。