LCGuard

LCGuard: Adversarial Training Framework for Safe KV Cache Sharing in Multi-Agent LLM Systems

LCGuard introduces a framework for preventing sensitive information leakage when multi-agent LLM systems share KV caches as a latent communication channel. The approach formalizes leakage operationally via reconstruction: a shared cache artifact is deemed unsafe if an adversarial decoder can recover sensitive inputs from it. An adversarial training loop pits a reconstructor against LCGuard's representation-level transformations, which aim to preserve task-relevant semantics while suppressing recoverable sensitive content. Empirical results across multiple model families and multi-agent benchmarks show reduced reconstruction-based leakage and attack success rates with competitive task performance.