Chain Reactions: How Nonce Collisions in ECDSA Compromise Polygon MEV Searchers

TL;DR

This paper reveals a critical vulnerability in Polygon's MEV ecosystem where nonce reuse in ECDSA signatures allows attackers to recover private keys, highlighting risks from latency-driven nonce predictability.

Contribution

It uncovers a systemic nonce reuse vulnerability in Polygon MEV searchers caused by latency constraints, providing a linear algebra-based attack model and real-world evidence.

Findings

Nonce reuse enables private key recovery in Polygon

Predictable nonce patterns are exploited by passive attackers

Latency pressures can cause cryptographic failures in blockchain systems

Abstract

ECDSA signatures form the bedrock of blockchain transaction authentication, yet their security critically depends on proper nonce generation. We uncover a critical vulnerability in the Polygon MEV ecosystem: systematic nonce reuse that enables complete private key recovery. Analyzing on-chain data reveals that searchers, driven by the need for sub-second response times in sealed-bid auctions, employ predictable nonce patterns. These patterns create linear relationships between signatures, allowing passive attackers to recover private keys using elementary algebra. We provide a compact linear-system formulation for such attacks, including the dangerous case of cross-wallet nonce collisions, and present concrete evidence of exploitable patterns on Polygon. Our findings demonstrate how protocol-induced latency pressures can lead to catastrophic cryptographic failures in production blockchain systems, where a single implementation error compromises multiple accounts simultaneously.