Practical PIR for electronic commerce

We extend Goldberg’s multi-server information-theoretic private information retrieval (PIR) with a suite of protocols for privacypreserving e-commerce. Our first protocol adds support for singlepayee tiered pricing, wherein users purchase database records without revealing the indices or prices of those records. Tiered pricing lets the seller set prices based on each user’s status within the system; e.g., non-members may pay full price while members may receive a discounted rate. We then extend tiered pricing to support group-based access control lists with record-level granularity; this allows the servers to set access rights based on users’ price tiers. Next, we show how to do some basic bookkeeping to implement a novel top-K replication strategy that enables the servers to construct bestsellers lists, which facilitate faster retrieval for these most popular records. Finally, we build on our bookkeeping functionality to support multiple payees, thus enabling several sellers t...

• Type: Journal
• Year: 2011
• Where: CCS
• Authors: Ryan Henry, Femi G. Olumofin, Ian Goldberg
• Keywords: CCS 2011, Open Source Implementation, Private Information Retrieval, Replication Strategy, Security Privacy