Probabilistic algorithms for both decision and search problems can offer significant complexity improvements over deterministic algorithms. One major difference, however, is that they may output different solutions for different choices of randomness. This makes correctness amplification impossible for search algorithms and is less than desirable in setting where uniqueness of output is important such as generation of system wide cryptographic parameters or distributed setting where different sources of randomness are used. Pseudo-deterministic algorithms are a class of randomized search algorithms, which output a unique answer with high probability. Intuitively, they are indistinguishable from deterministic algorithms by an polynomial time observer of their input/output behavior. In this talk I will describe what is known about pseudo-deterministic algorithms in the sequential, sub-linear and parallel setting. We will also briefly describe an extension of pseudo-deterministic algorithms to interactive proofs for search problems where the verifier is guaranteed with high probability to output the same output on different executions, regardless of the prover strategies. Based on Joint work with Gat, Goldreich, Ron, Grossman and Holden.
Shafi Goldwasser is the RSA Professor of Electrical Engineering and Computer Science at MIT. She is also a professor of computer science and applied mathematics at the Weizmann Institute of Science in Israel. Goldwasser pioneering contributions include the introduction of interactive proofs, zero knowledge protocols, hardness of approximation proofs for combinatorial problems, and multi-party secure protocols. She was the recipient of the ACM Turing Award for 2012, the Gödel Prize in 1993 and another in 2001, the ACM Grace Murray Hopper award, the RSA award in mathematics, the ACM Athena award for women in computer science, the Benjamin Franklin Medal, and the IEEE Emanuel R. Piore award. She is a member of the AAAS, NAS and NAE.