Learn More
We propose a new, communication-efficient way for users to fetch multiple blocks simultaneously in Goldberg's robust information-theoretic private information retrieval (IT-PIR) scheme. Our new multi-block IT-PIR trades off some Byzantine robustness to improve throughput without affecting user privacy. By taking advantage of the recent Cohn-Heninger(More)
We extend Goldberg's multi-server information-theoretic private information retrieval (PIR) with a suite of protocols for privacy-preserving e-commerce. Our first protocol adds support for single-payee tiered pricing, wherein users purchase database records without revealing the indices or prices of those records. Tiered pricing lets the seller set prices(More)
We propose a new system modeled after Nymble. Like Nymble, our scheme provides a privacy-preserving analog of IP address blocking for anonymizing networks. However, unlike Nymble, the user in our scheme need not trust third parties to maintain their anonymity. We achieve this while avoiding the use of trusted hardware and without requiring an offline(More)
—Anonymous communications networks, such as Tor, help to solve the real and important problem of enabling users to communicate privately over the Internet. However, in doing so, anonymous communications networks introduce an entirely new problem for the service providers—such as web-sites, IRC networks or mail servers—with which these users interact ; in(More)
We present a practical attack on soundness in Peng and Bao's 'batch zero-knowledge proof and verifica-tion' protocol for proving knowledge and equality of one-out-of-n pairs of discrete logarithms. Fixing the protocol seems to require a commitment scheme with a nonstandard, mercurial-esque binding property: the prover commits to just n − 1 values, but later(More)
We present BLACRONYM, a suite of new communication- and computation-efficient protocols for anonymous blacklisting without trusted third parties. Our protocols improve on Tsang et al.'s Blacklistable Anonymous Credentials (BLAC) system and its variants by incorporating novel batch zero-knowledge proof and verification techniques. BLACRONYM provides(More)
Private information retrieval (PIR) is a way for clients to query a remote database without the database holder learning the clients' query terms or the responses they generate. Compelling applications for PIR are abound in the cryptographic and privacy research literature, yet existing PIR techniques are notoriously inefficient. Consequently, no such(More)
We present BLACRONYM, a suite of new communication-and computation-efficient protocols for anonymous blacklisting without trusted third parties. Our protocols improve on Tsang et al.'s Black-listable Anonymous Credentials (BLAC) system and its variants by incorporating novel batch zero-knowledge proof and verification techniques. BLACRONYM provides(More)
  • 1