DNA-BASED STEGANOGRAPHY

Abstract

This paper presents an implementation of steganography using DNA molecules. We first encode a plaintext message into a DNA sequence using a randomly generated single-substitution key. An oligonucleotide containing the encoded message, designated the message strand, is synthesized and mixed with a large amount of background DNA. To retrieve the message, the intended recipient must know the sequences of two primers that anneal to target regions present on the message strand. Polymerase chain reaction (PCR) and sequencing are used to retrieve the encoded sequence, which is decoded into the original plaintext via the single substitution key. This study shows that the steganographically hidden message can be retrieved only by using the two secret primers, meaning that the only applicable cryptanalytic approach is a brute-force search for the two primer sequences. Since each primer can have 420 different possible sequences, the amount of time required to crack DNA-based steganography is long enough to qualify the technique as essentially unbreakable.