# SPHINCS$^+$ post-quantum digital signature scheme with Streebog hash function

## TL;DR

This paper evaluates the use of the Russian Streebog hash function in the SPHINCS$^+$ post-quantum digital signature scheme, comparing its performance with SHA-256-based versions through benchmarks.

## Contribution

It introduces the implementation and performance analysis of Streebog within SPHINCS$^+$, a promising post-quantum signature scheme, highlighting its efficiency and practicality.

## Key findings

- Streebog-based SPHINCS$^+$ shows comparable performance to SHA-256 versions.
- Benchmark results demonstrate the viability of Streebog for post-quantum signatures.
- Performance varies with different parameter sets, indicating flexibility in deployment.

## Abstract

Many commonly used public key cryptosystems will become insecure once a scalable quantum computer is built. New cryptographic schemes that can guarantee protection against attacks with quantum computers, so-called post-quantum algorithms, have emerged in recent decades. One of the most promising candidates for a post-quantum signature scheme is SPHINCS$^+$, which is based on cryptographic hash functions. In this contribution, we analyze the use of the new Russian standardized hash function, known as Streebog, for the implementation of the SPHINCS$^+$ signature scheme. We provide a performance comparison with SHA-256-based instantiation and give benchmarks for various sets of parameters.