Paper 2019/420

Improving Speed of Dilithium’s Signing Procedure

Prasanna Ravi and Sourav Sen Gupta and Anupam Chattopadhyay and Shivam Bhasin

Abstract

In this short note, we propose an optimization to improve the signing speed of Dilithium's signing procedure. Our optimization works by reducing the number of computations in the rejected iterations through Early-Evaluation of the rejection condition. We would like to note that this straightforward algorithmic optimization only reduces the computational overhead in every rejected iteration, without having any effect on the rejection rate. We perform experimental validation of our optimization through software implementation on an Intel(R) Core(TM) i5-4460 CPU and observe observe a speed up of about 7-8% of Dilithium's signing procedure for recommended parameter sets of Dilithium. Moreover, this optimization is also implementation agnostic and hence can be ported to all implementation platforms.