Some possible codes for encrypting data in DNA.

Three codes are reported for storing written information in DNA. We refer to these codes as the Huffman code, the comma code and the alternating code. The Huffman code was devised using Huffman's algorithm for constructing economical codes. The comma code uses a single base to punctuate the message, creating an automatic reading frame and DNA which is obviously artificial. The alternating code comprises an alternating sequence of purines and pyrimidines, again creating DNA that is clearly artificial. The Huffman code would be useful for routine, short-term storage purposes, supposing--not unrealistically--that very fast methods for assembling and sequencing large pieces of DNA can be developed. The other two codes would be better suited to archiving data over long periods of time (hundreds to thousands of years).