Platform compares attacks and defenses for testing language models

ACEA: An Adversarial Co-Evolution Arena for Head-to-Head Red-Team and Blue-Team LLM Testing

Cryptography and SecurityArtificial Intelligence

Summary

Testing how well large language models can defend against attacks is usually done separately for attackers and defenders, making it hard to trust the results. The authors designed a system called ACEA that lets attackers and defenders face off against the same language model and measures who does better in each round. They include methods to check if attacks actually reveal real secrets rather than mistakes, and show results in a way that helps improve both attackers and defenders. Their system can also give advice to improve strategies during testing without needing to remember past rounds.

large language modelsred teamblue teamadversarial testingmodel evaluationsecurity testingHTTP protocolground truthin-context learningattack-defense metrics

Authors

Yi Ting Shen, Kentaroh Toyoda, Alex Leung

Abstract

Automated red-team attacks and blue-team defenses for large language models (LLMs) are advancing quickly. However, attackers and defenders are built and tested in isolation, and the resulting scores are hard to trust. To tackle this, we present ACEA (Adversarial Co-Evolution Arena), a platform that connects a pluggable red-team adapter and a pluggable blue-team adapter to a shared target LLM and scores their attack and defense rates with an LLM judge. ACEA contributes four components. First, a pluggable, model-agnostic arena. Any red or blue project connects over a minimal HTTP protocol, which we call the ACEA Standard Adapter Protocol (ASAP). It can be written in any language, and a project that exposes nothing but the protocol is a full participant. Second, an evaluation methodology built for adversarial rounds. Seeding the target with canonical secrets gives verifiable ground truth that separates real leakage from hallucination. We also send each attack to the target even when the defense blocks it, which measures the attack's raw potency independently of whether it was stopped. Together these yield a per-round decomposition of attack strength and defense effectiveness. Third, a real-time, game-style visualization with a detailed end-of-battle report that localizes each failure. The evaluation thus becomes an actionable signal for improving a red or blue project. Fourth, an optional in-context improvement loop that turns each round's outcome into advisory hints for the next. An adapter can then adapt across rounds without keeping state, provided it reads the hints. We describe the design of ACEA and the metrics through which red and blue teams are scored head to head.