Encryption in DNA
Researchers at the Center for Integrated Nanotechnology of the Sandia National Laboratories of the USA, working under the leadership of George Bachand, are working on a new exceptionally reliable method of encoding and storing important information. They propose to use DNA as a data carrier, the uniqueness of which lies in its unprecedented compactness and durability. So, even from the horse remains found in the Yukon River, which are about 600,000 years old, "readable" DNA was isolated.
The films and disks used for storing information can wear out and fail, so they need to be rewritten regularly about once a decade. Storing data on servers or in cloud storage requires huge energy costs. The electricity consumed by Google's servers in 2011 would have been enough to power 200,000 homes in the United States. Moreover, the old methods of storing information require a lot of space.
Bachand was inspired to work with DNA by the latest achievements in this field (a recent record – Microsoft specialists managed to record 200 MB of information in a barely visible drop at the bottom of a test tube).
As part of their project, Bachand and his colleagues used an almost indecipherable encryption key to encode an abbreviated version of President Harry Truman's historic letter in DNA. After that, they synthesized a DNA molecule, put it on the printed letterhead of the institution and sent it along with an ordinary paper letter to travel around the country. After returning the letter, they successfully extracted DNA from the paper, amplified it and decoded the message for about 24 hours. The cost of this procedure was approximately $45.
The first stage of this project was the development of software that generates an encryption key and encodes the text into a DNA sequence.
DNA consists of four types of nucleic bases, usually denoted by letter abbreviations: A (adenine), C (cytosine), G (guanine) and T (thymine). With the help of a triplet (triplet – 3 consecutive nucleotide bases) code used by all living organisms to encode genetic information, 64 different characters (letters, spaces and punctuation marks) can be encoded, which are enough to encrypt information with a margin.
For example, spaces on average account for 15-20% of the volume of a text document. According to the TAG cipher code, TAA and TGA can encode spaces, whereas GAA and CTC can encode the letter "E". This will reduce the number of repetitions, which will technically complicate the synthesis and reading of DNA, while making it difficult for unauthorized decryption of the text.
The authors began coding experiments by encrypting a message of 180 characters with spaces. They note that encoding the message itself into 550 nucleotide bases was an easy task, and the subsequent DNA synthesis turned out to be time-consuming and expensive. However, the achievements of recent years in the synthesis of artificial DNA from so-called gene blocks have greatly facilitated the work and researchers soon managed to encrypt Truman's 700-character letter with spaces. They are currently working on even longer sequences.
The method of coding the test in DNA developed by Bachand's group. With the help of a computer algorithm, the text is encoded into a sequence of nucleotides. After that, the researchers synthesize the corresponding DNA strand, which can be read using sequencing technology and decoded using the same computer algorithm.
The ultimate goal of the work is to use the developed approach to solve national security problems. Two possible approaches to its application described by the authors are the storage of historical confidential documents, as well as bar coding/watermarking on electromechanical components, such as computer chips.
The researchers note that storing information in the form of DNA is much less expensive compared to traditional methods and does not require huge storage facilities. At the same time, the conversion of information from solid carriers into DNA is a very complex process involving scanning, decoding and DNA synthesis. DNA synthesis is the most expensive stage of this process, but its cost has significantly decreased over the past few years and continues to decrease.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Sandia National Laboratories: Sandia storing information securely in DNA.
15.07.2016