XCRYPT: Accelerating Lattice-Based Cryptography With Memristor Crossbar Arrays

Abstract

This paper makes a case for accelerating lattice-based post quantum cryptography with memristor-based crossbars. We map the polynomial multiplications in a representative algorithm, SABER, and show that analog dot-products can yield 1.7 − 32.5× performance and energy efficiency improvement, compared to recent hardware proposals. We introduce several additional techniques to address the bottlenecks in this initial design. First, we show that software techniques used in SABER, that are effective on CPU platforms, are unhelpful in crossbars. Relying on simpler algorithms further improves our efficiency by 1.3 − 3.6×. Second, modular arithmetic in SABER offers an opportunity to drop most significant bits, enabling techniques that exploit a few variable precision ADCs, and yielding up to 1.8× higher efficiency. Third, to further reduce ADC pressure, we propose a simple analog Shift-and-Add technique, demonstrating a 1.3 − 6.3× improvement. Overall, XCRYPT achieve 3 − 15× higher efficiency over the initial design and highlight the importance of algorithm-accelerator co-design.