Abstract: Different from cryptography which encodes data into an incomprehensible format difficult to decrypt, steganography hides the trace of data and therefore minimizes attention to the hidden data. To hide data, a carrier body must be utilized. In addition to the traditional data carriers including images, audios, and videos, DNA emerges as another promising data carrier due to its high capacity and complexity. Currently, DNA based steganography can be practiced with either biological DNA substances or digital DNA sequences. In this article, we present a digital DNA steganography approach that utilizes the CRISPR-Cas9 off-target editing such that the secret message is fragmented into multiple sgRNA homologous sequences in the genome. Retrieval of the hidden message mimics the Cas9 off-target detection process which can be accelerated by computer software. The feasibility of this approach is analyzed, and practical concerns are discussed.
Keywords: DNA; steganography; CRISPR; Cas9; sgRNA; off-target; substitution