Information Security Applications Based on Biomolecular Systems

Abstract

IntroductionModern computers rely on networked logic gates performing Boolean operations to carry out binary computational functions. By extending the same digital paradigms to molecular [1][2][3][4] and biomolecular computing systems [5,6], chemical processes can mimic electronic counterparts and perform logic operations. For example, Boolean logic gates such as AND, OR, XOR, NOR, NAND, and INHIB, have been demonstrated based on switchable molecular systems [1][2][3][4]. In addition, a wide range of biomolecules have been used for information processing [5,6]. The simplicity of biomolecular processing is attributed to the inherent substrate specificity and versatility of biomolecules; thus the application of biomolecular systems for processing chemical and biochemical information has reached high levels of complexity, despite employing only simple chemical signals.Compared to the advanced power and complexity of computing performed in silico, molecular and biomolecular computing is primitive; however, biomolecular information processing has a niche application in small portable devices that rely on a specific bioelectronic interface. In this area of technological development, portable biomedical sensors [7] with built-in diagnostic capabilities and controlled by simple biomolecular logic operations can be realized [8][9][10][11].Despite significant advances in DNA-based computing [12][13][14], examples of enzyme-based computing are sparse, but the inherent advantage that enzymes exhibit over DNA is catalytic specificity. To date, enzyme-based logic gates using chemical inputs have been demonstrated for XOR, INHIBIT A, INHIBIT B, AND, OR, NOR, Identity, and Inverter Boolean operators [15,16]. These single logic gates all operate as independent systems, that is, the output does not act as an input for a subsequent logic operation. In contrast, biocatalytic logic systems with increased complexity can be designed by defining specific reaction cascades [17]. In fact, biocatalytic cascades found in Nature provide insight into engineering such systems. Thus, by combining enzymes with interconnected and compatible reactions, Baron et al. [16] have demonstrated half-adder and Biomolecular Information Processing: From Logic Systems to Smart Sensors and Actuators, First Edition. Edited by Evgeny Katz.

Message in a molecule

“…Unlike its predecessor414243, however, or any other fluorescent probe that responds to several analytes2444 or an analyte group43, m-SMS was designed to operate as a universal sensor that can discriminate among a vast number of distinct chemical species. We show that this property not only distinguishes m-SMS from other types of fluorescent molecular sensors, but also from other chemical security systems45678910111213141516171819202122272829303132333435363738394041 by enabling it to function as a molecular cipher device that can convert distinct chemical structures into unique encryption keys. In this way, the system can be used not only to hide the data (steganography), but also to encrypt and decrypt it (cryptography), as well as provide password protection when a higher level of security is needed.…”

“…Another important advantage of using molecular steganography systems, namely, their small scale, has also been demonstrated by the ability to conceal messages within individual DNA strands21. Finally, advances in the area of molecular logic gates2223242526 have resulted in alternative methods of securing information222728 by using multi-analyte fluorescent molecular sensors that can produce ID-codes29 or can authorize password entries303132333435363738394041.…”