Obfuscation as an Effective Signal for Prioritizing Cross-Chain Smart Contract Audits: Large-Scale Measurement and Risk Profiling

TL;DR

This paper introduces HOBFNET, a fast, scalable model for cross-chain smart contract risk scoring based on obfuscation signals, enabling efficient prioritization of audits across multiple blockchain ecosystems.

Contribution

The paper presents HOBFNET, a novel surrogate model that significantly accelerates cross-chain smart contract scoring and provides a practical workflow for security operations.

Findings

HOBFNET achieves 8-9 ms per contract with high accuracy.

Systematic score drift observed across chains motivates new queue strategies.

High-score tail features support secondary triage and risk assessment.

Abstract

Obfuscation raises the interpretation cost of smart-contract auditing, yet its signals are hard to transfer across chains. We present HOBFNET, a fast surrogate of OBFPROBE, enabling million-scale cross-chain scoring. The model aligns with tool outputs on Ethereum (PCC 0.9158, MAPE 8.20 percent) and achieves 8-9 ms per contract, yielding a 2.3k-5.2k times speedup. Across BSC, Polygon, and Avalanche, we observe systematic score drift, motivating within-chain percentile queues (p99 as the main queue, p99.9 as an emergency queue). The high-score tail is characterized by rare selectors, external-call enrichment, and low signature density, supporting secondary triage. Cross-chain reuse is tail-enriched and directionally biased from smaller to larger ecosystems. On two publicly alignable cross-chain spillover cases, both fall into the p99 queue, indicating real-world hit value. We deliver a two-tier audit queue and a cross-chain linkage workflow for practical security operations.