SentinelRAG: Synthetic Sentinel Knowledge for RAG Database Copyright Protection

Computer Science > Cryptography and Security [Submitted on 4 Jun 2026] SentinelRAG: Synthetic Sentinel Knowledge for RAG Database Copyright Protection Tsun On Kwok, Xi Yang, Ki Sen Hung, Chang Liu, Yangqiu Song Protecting proprietary RAG databases from unauthorized redistribution is challenging: existing watermarking methods either inject fabricated relations between real entities, polluting the knowledge base with misinformation, or embed fragile lexical patterns that adversarial paraphrasing easily removes. We propose SentinelRAG, a watermarking framework that embeds style-consistent but fictitious knowledge entries into the RAG database. Our key insight is that synthetic knowledge describing fictitious entities is unlikely to be retrieved by legitimate queries, yet can be reliably triggered through targeted probes known only to the data owner. Experiments on four datasets ranging from 2.9k to 8.8M documents demonstrate that SentinelRAG achieves statistically significant detection p < 10^{-5} across all tested configurations at only a 0.1% injection rate. Compared to the state-of-the-art, our method significantly reduces the false detection rate while maintaining negligible interference with legitimate user queries. Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2606.05787 [cs.CR]   (or arXiv:2606.05787v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2606.05787 Focus to learn more Submission history From: Tsun On Kwok [view email] [v1] Thu, 4 Jun 2026 07:19:56 UTC (2,306 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-06 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)