Cryptography with Analog Scheme Using Memristors

Abstract

Networks of low-power Internet of Things do not have always access to enough computing power to support mainstream cryptographic schemes; such schemes also consume computing power that can be exposed to side channel attacks. This article describes a method, that we call “cryptography with analog scheme using memristors,” leveraging the physical properties of memristors, which are active elements suitable for the design of components such as artificial neurons. The proposed devices encrypt messages by segmenting them into blocks of bits, each modulating the injected currents into randomly selected memristor cells, resulting into sets of resistance values turned into cipher texts. Through hash-protected handshakes, identical addresses are independently generated by both communicating devices, to concurrently point at the same set of cells in the arrays, and their images. These block ciphers, for example, 1 KB long, can only be decrypted with the same memristor array driven by analog circuitry or its image, rather than digital key-based schemes. The proposed methods generate cipher text, and decrypt them, with approximately one femto joule per bit, which is below observable level through differential power analysis. The article explains how the use of different cells for each message to encrypt, driven under different conditions, has the potential to mitigate mainstream attacks. It provides a detailed characterization of memristors to evaluate the feasibility of the approach and discusses some hardware and architectures to implement the scheme.

Statistical Analysis of ReRAM-PUF based Keyless Encryption Protocol Against Frequency Analysis Attack

“…Another drawback of using keys for cryptography, however, is the large memory space allocated for key storage in devices. Most of the IoT devices do not possess ample memory space due to cost constraints and limited power supply [3,4,5]. This means that the problem of longer secret keys and strong cryptography systems can be hard to implement in IoT devices.…”

“…A keyless encryption scheme, which uses memristors technology, is developed by Bertrand Cambou et. al [3]. This protocol uses a memristor PUF (see table 1) to create ciphertext without generating a key.…”

“…In 2017, [12] mentioned that "the injection of low currents in cells of memristor arrays, can result in dissolvable conductive paths of vari able resistances, and can be exploited to design Physical Unclonable Functions (PUFs)." Articles [3] and [13] describe how a memristor PUF is used to encrypt plaintext without using an encryption key. Through exploiting the features of memristor, the output of memristors becomes the cipher.…”

“…After subjecting the current to a specific cell, the output will be the value of resistance. As shown in [3] and [13] , resistance values with the current value can make ciphertext. Repeatedly visiting the same cell in the memristor can help hackers exploit frequency analysis attacks to extract the plaintext.…”

“…Repeatedly visiting the same cell in the memristor can help hackers exploit frequency analysis attacks to extract the plaintext. According to [3], the ReRAM cells have been used to generate a ciphertext. This paper is going to focus on studying the randomness of visiting each cell in the memristor.…”