Machine Against the RAG: Jamming Retrieval-Augmented Generation with Blocker Documents

Avital Shafran, Roei Schuster, Vitaly Shmatikov

34th USENIX Security Symposium · Day 1

This paper introduces and rigorously evaluates a novel class of denial-of-service vulnerabilities in **Retrieval-Augmented Generation (RAG)** systems, termed **jamming attacks**. Authored by Avital Shafran, Roei Schuster, and Vitaly Shmatikov, the research reveals that an adversary can prevent a RAG system from answering specific queries by injecting a single, carefully crafted "blocker" document into its knowledge database. The attack is particularly insidious because it causes the LLM to refuse to answer, often citing plausible reasons such as insufficient information or safety concerns, making it stealthy and difficult to fact-check.

AI review

This is the RAG security paper people will be citing for the next three years. Clean threat model, novel black-box optimization method that actually works, and the uncomfortable finding that 'safer' LLMs are *more* jammable. Real research that moves the field.