Embellishing text search queries to protect user privacy

Users of text search engines are increasingly wary that their ac-tivities may disclose confidential information about their business or personal profiles. It would be desirable for a search engine to perform document retrieval for users while protecting their intent. In this paper, we identify the privacy risks arising from semanti-cally related search terms within a query, and from recurring high-specificity query terms in a search session. To counter the risks, we propose a solution for a similarity text retrieval system to offer anonymity and plausible deniability for the query terms, and hence the user intent, without degrading the system’s precision-recall per-formance. The solution comprises a mechanism that embellishes each user query with decoy terms that exhibit similar specificity spread as the genuine terms, but point to plausible alternative top-ics. We also provide an accompanying retrieval scheme that en