arXiv AI By Jiacheng Liang, Yuhui Wang, Tanqiu Jiang, Ting Wang

LaCache: Robust Semantic Caching for LLM Serving

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LaCache introduces a redesigned semantic caching mechanism for large language model (LLM) serving that defends against cache‑collision attacks. By shifting integrity checks from queries to the first $k$ speculatively decoded tokens of the LLM response, LaCache can detect adversarial cache pollution with provable high probability. Experiments across multiple LLMs and benchmarks show that LaCache reduces attack hit rates to near zero while retaining over 90% of benign cache utility.

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