DNA cryptography based on DNA Fragment assembly

In this paper, the authors introduce the background of DNA cryptography, and briefly describe the features of DNA molecular, key bio-technologies and related software. And then the authors study the difficult biological problem which is the key and basic part in designing of DNA encryption, and put forward our own difficult problem which is that it is difficult to assembly when overlaps are destroyed and prove its difficulty with examples. After analysis of encoding of DNA and mechanism of symmetric encryption, the authors design a symmetric system using the technology of DNA digital coding and DNA fragment assembly. The security analysis proves that the scheme has high confidential strength.