# Cryptanalysis of a One-Time Code-Based Digital Signature Scheme

## TL;DR

This paper demonstrates a practical key recovery attack on a recent one-time code-based digital signature scheme, exploiting signature sparsity and statistical analysis to significantly reduce the security level.

## Contribution

It introduces a novel attack method that recovers secret keys from a single intercepted signature, challenging the claimed security of the scheme.

## Key findings

- Successful key recovery with low complexity
- Attack exploits signature sparsity and statistical analysis
- Security level claims are significantly undermined

## Abstract

We consider a one-time digital signature scheme recently proposed by Persichetti and show that a successful key recovery attack can be mounted with limited complexity. The attack we propose exploits a single signature intercepted by the attacker, and relies on a statistical analysis performed over such a signature, followed by information set decoding. We assess the attack complexity and show that a full recovery of the secret key can be performed with a work factor that is far below the claimed security level. The efficiency of the attack is motivated by the sparsity of the signature, which leads to a significant information leakage about the secret key.