Bloom Cookies: Web Search Personalization without User Tracking

—We propose Bloom cookies that encode a user’s profile in a compact and privacy-preserving way, without preventing online services from using it for personalization purposes. The Bloom cookies design is inspired by our analysis of a large set of web search logs that shows drawbacks of two profile obfuscation techniques, namely profile generalization and noise injection, today used by many privacy-preserving personalization systems. We find that profile generalization significantly hurts personalization and fails to protect users from a server linking user sessions over time. Noise injection can address these problems, but only at the cost of a high communication overhead and a noise dictionary generated by a trusted third party. In contrast, Bloom cookies leverage Bloom filters as a privacy-preserving data structure to provide a more convenient privacy, personalization, and network efficiency tradeoff: they provide similar (or better) personalization and privacy than noise ...

• Type: Journal
• Year: 2015
• Where: NDSS
• Authors: Nitesh Mor, Oriana Riva, Suman Nath, John Kubiatowicz
• Keywords: Computer Networks, NDSS 2015