I am interested in such problems as efficient and provably secure cryptographic schemes and protocols, in minimal complexity assumptions for achieving security for various applications, and in secure distributed computation.

The main thrust of my research is on practical cryptographic tools for privacy-preserving transactions. A typical computer user performs a multitude of electronic transactions each day: reading e-mail, managing bank accounts, making on-line purchases, to name a few. Each of them must be secure: they should be carried out by authorized users only, and the information entered must be authentic. On the other hand, each transaction should be private: personal information or account balances should not become available without a user's explicit consent. It is highly desirable to limit the information transmitted in each transaction to a bare minimum without compromising its authenticity. In particular, since data aggregation is simple to do, there should be no information revealed that can link a transaction to another transaction carried out by the same individual.

Please send good papers to and attend the following upcoming conferences: Eurocrypt 2007, PKC 2007, IEEE Security and Privacy 2007, ICALP 2007, Asiacrypt 2007, FOCS 2007 (coming to Providence!), Eurocrypt 2008.

Current Ph.D. students: Mira Belenkiy (nee Meyerovich), Melissa Chase, Alptekin Küpçü.

In Fall 2007 I will be teaching "CSCI0510: Models of Computation".
In Spring 2008 I will teach "CSCI2590: Advanced Topics in Cryptography"; this year's emphasis will be on zero-knowledge proofs.