Design Patterns which Facilitate Message Digest Collision Attacks on Blockchains

TL;DR

This paper analyzes how message digest collision vulnerabilities can be exploited in blockchain platforms like Ethereum and proposes mitigations such as longer digest sizes and timeliness constraints to enhance security.

Contribution

It identifies specific attack scenarios on blockchain message digests and introduces practical mitigations to prevent collision-based exploits.

Findings

Longer message digests increase attack difficulty

Timeliness properties limit collision attack opportunities

Analysis applicable to Ethereum and similar platforms

Abstract

Message digest algorithms are one of the underlying building blocks of blockchain platforms such as Ethereum. This paper analyses situations in which the message digest collision resistance property can be exploited by attackers. Two mitigations for possible attacks are described: longer message digest sizes make attacks more difficult; and, including timeliness properties limits the amount of time an attacker has to determine a hash collision.