IntroductionDNA Computation is one of the areas of natural computation based on the idea that molecular biology process can be used to perform arithmetic and logical operations and encode information in strands of DNA. DNA computation primarily uses DNA analogues and RNA for computational purposes. DNA computing uses the manipulation of biomolecules to solve computational problems and explore a natural process as computational models. The idea is to encode data into strands of DNA and use tools to solve difficult computational problems. First DNA Calculation The first DNA calculation ever created was done in 1994 by Leonard Adleman, who performed the calculation using DNA strands. Leonard Adleman implements his DNA calculation to solve the Hamiltonian path problem (HPP) using a brute force algorithm. HPP is one of the problems in the study of complex network and graph theory and belongs to the class of problems known as NP-complete. NP-complete is one of the most difficult problems which includes theoretical and practical meaning such as network design, scheduling and data storage. So, to solve this problem, Adleman uses few approaches that use DNA computation. [1]There are three steps that were performed by Adleman:1) Generate strands that encode random paths2) Remove all strands that do not encode HP3) Check that the remaining strands encode a solution for HPPIn the first step each vertex and edge has been assigned as a 20-base sequence of DNA. The sequence indicating the edges acts as a cue between the threads representing their endpoints. Each oligo was combined from strands encoding random paths through the graph. Then a fixed amount of oligo, about 50 pmol, was synthesized, mixed together, and then ligase added to seal any backbone... half of the paper... of cryptography called cryptography seems unreliable as it used plain text, but Authentication of DNA and shorthand have proven useful in the field. DNA computing has been proven to handle difficult computational problems and still has the potential to solve even more complex problems and replace the electric computer in the future. Reference[1]A.Martyn(2008). DNA Computing[Online]: http://www2.docm.mmu.ac.uk/STAFF/M.Amos/Docs/dnacomp.pdf[2]SM Mohd, I.Zuwairie, U.Satomi, O.Osamu, K .Marzuki(2005). DNA computation for complex planning problems[Online]. Available: http://www.isc.meiji.ac.jp/~onosemi/IADC/ICNCSaufee.pdf[3]C. Guangzhao, L. Cuiling, L. Xiaoguang (2010, February). DNA computing and its application to the field of information security.[Online] Available: http://csis.bits-pilani.ac.in/faculty/murali/netsec-10/seminar/refs/ramakrishna3.pdf