JOURNAL OF SOFTWARE ENGINEERING & INTELLIGENT SYSTEMS ISSN 2518-8739 30 th April 2018, Volume 3, Issue 1, JSEIS, CAOMEI Copyright © 2016-2018 www.jseis.org 67 DNA-based cryptography: motivation, progress, challenges, and future A.E. El-Moursy, Mohammed Elmogy, Ahmad Atwan Information Technology Dept., Faculty of Computers and Information, Mansoura University, Egypt Email: abdullaelsaied@yahoo.com, melmogy@mans.edu.eg, atwan_2@yahoo.com ABSTRACT Cryptography is about constructing protocols by which different security means are being added to our precious information to block adversaries. Properties of DNA are appointed for different sciences and cryptographic purposes. Biological complexity and computing difficulties provide twofold security safeguards and make it difficult to penetrate. Thus, a development in cryptography is needed not to negate the tradition but to make it applicable to new technologies. In this paper, we review the most significant research, which is achieved in the DNA cryptography area. We analysed and discussed its achievements, limitations, and suggestions. In addition, some suggested modifications can be made to bypass some detected inadequacies of these mechanisms to increase their robustness. Biological characteristics and current cryptography mechanisms limitations were discussed as motivations for heading DNA-based cryptography direction. Keywords: DNA; cryptography; encryption; DNA computing; bio-inspired cryptography; 1. INTRODUCTION Technological development seizes our valuable information including financial transactions are transmitted back and forth in public communication channels, posing a considerably high challenge in confronting with unintended intruders. One suggestion is cryptography that is about constructing protocols built strong mathematically and theoretically by which different security means are being added to such precious information. DNA computing is a new science emerged in recent years clarifying to be very efficient in energy consumption, high information storage capability and parallel processing. Deoxyribonucleic Acid is molecules formed in a certain sequence to construct the information needed for building and maintaining the vital operations of an organism, similar to the way in which binary bits appear in certain order to form different information in our digital world [1]. 1.1 DNA computer DNA computer or biomolecular computer is a computer its input, system, and output is wholly or partially made of DNA molecules, biochemistry, and molecular biology hardware instead of silicon chips technologies. The complexity and ingenuity of living beings are built based on a simple coding system functioning with only four components of DNA molecule similar to the binary coding system of traditional computers. This coding system make DNA is very suited as a medium for data storing and processing. 1.2 DNA biological anatomy DNA is a blueprint for the living organism; it carries instruction for functioning vital processes. DNA is a collection of molecules stuck together to form a long chain of strands, a certain combination of these DNA strands forms amino acids which are the building block of a living organism. Amino Acids, in turn, combines to form protein, proteins create living cells, and cells create organs. The bases of DNA nucleotides are of four types (guanine, adenine, thymine, and cytosine) labelled as G, A, T, and C; respectively and usually exists in nature in the form of double-stranded molecules, see Figure 1. Human DNA consists of about 3*109 bases, and more than 99 percent of those bases are quite similar to all people.