Memristor-Based Lightweight Encryption

TL;DR

This work investigates using memristor technology to implement a lightweight block cipher suitable for ultra-resource-constrained edge healthcare devices. By mapping the GIFT-128 cipher onto a 40-nm 1T1R RRAM crossbar, the authors enable single-read encryption rounds and reuse hardware across 40 rounds, achieving a total area of $0.0034\ \mathrm{mm}^2$ and encryption energy of $\$242\ \mathrm{pJ}$ per 128-bit block. The design employs non-volatile, reconfigurable substitution boxes and two XOR implementations (SXOR and DXOR) to balance energy and area while providing side-channel resilience. The DXOR-GIFT variant shows markedly better energy efficiency than SXOR-GIFT, with similar area, highlighting memristor-based crossbars as a viable path for ultra-lightweight encryption in edge devices. Overall, the work demonstrates that memristor-based light cryptography can meet the stringent power, area, and security requirements of next-generation personalized healthcare edge systems, while enabling run-time SB reconfiguration to mitigate side-channel threats.

Abstract

Next-generation personalized healthcare devices are undergoing extreme miniaturization in order to improve user acceptability. However, such developments make it difficult to incorporate cryptographic primitives using available target technologies since these algorithms are notorious for their energy consumption. Besides, strengthening these schemes against side-channel attacks further adds to the device overheads. Therefore, viable alternatives among emerging technologies are being sought. In this work, we investigate the possibility of using memristors for implementing lightweight encryption. We propose a 40-nm RRAM-based GIFT-cipher implementation using a 1T1R configuration with promising results; it exhibits roughly half the energy consumption of a CMOS-only implementation. More importantly, its non-volatile and reconfigurable substitution boxes offer an energy-efficient protection mechanism against side-channel attacks. The complete cipher takes 0.0034 mm$^2$ of area, and encrypting a 128-bit block consumes a mere 242 pJ.

Figures (7)

• Figure 1: Basic structure of a 1T1R crossbar array.
• Figure 2: Architecture of GIFT-64 banik2017gift. The encircled section (in blue) denotes a slice of a single round of encryption. The substitution specification of a 4-bit SB is shown on the right.
• Figure 3: Top view of the memristor-based GIFT cipher.
• Figure 4: The slice architecture of the 1T1R GIFT cipher and operation sequence corresponding to a round of encryption.
• Figure 5: SXOR: VSA-based Scouting Logic XOR.