Anonymizing Query Logs by Differential Privacy

Abstract

Query logs are valuable resources for Information Retrieval (IR) research. However, because they are also rich in private and personal information, the huge concern of leaking user privacy prevents query logs from being shared from the search companies to the broad research community. Bothered by the lack of good research data for years, the authors of this paper are motivated to explore ways to generate anonymized query logs that can still be effectively used to support the search task. We introduce a framework to anonymize query logs by differential privacy, the latest development in privacy research. The framework is empirically evaluated against multiple search algorithms on their retrieval utility, measured in standard IR evaluation metrics, using the anonymized logs. The experiments show that our framework is able to achieve a good balance between retrieval utility and privacy.