Attacking an OT-Based Blind Signature Scheme

TL;DR

This paper presents a practical attack on an OT-based blind signature scheme exploiting partial MITM behavior, demonstrating communication corruption, and proposes a fix to enhance security.

Contribution

It introduces a novel attack method on an existing blind signature scheme and provides a security fix to prevent such vulnerabilities.

Findings

The attack can corrupt protocol communication with minimal computational effort.

The attack exploits specific-range random number generation and partial MITM behavior.

A proposed solution effectively mitigates the identified security flaw.

Abstract

In this paper, we describe an attack against one of the Oblivious-Transfer-based blind signatures scheme, proposed in [1]. An attacker with a primitive capability of producing specific-range random numbers, while exhibiting a partial MITM behavior, is able to corrupt the communication between the protocol participants. The attack is quite efficient as it leads to a protocol communication corruption and has a sound-minimal computational cost. We propose a solution to fix the security flaw.