Abstract
Modern studies focused on Deoxyribonucleic acid (DNA) because that DNA have several important features including the random nature of the sequence of nitrogenous bases consisting the acid and large storage capability of the information that led to it’s usage in the field of encryption where the appearance of a new branch which is encryption of DNA . This research provided a new method to encrypt text files using DNA were building a set of coding tables and using them to obtain the cipher text in DNA form , also used a set of transposition cipher methods for the purpose of increasing the security of the resulted cipher text .