CSIS Seminar

From Theory to Practice: From Zero-Knowledge via Secure Computation to a Next-Generation Signature Scheme

Abstract

Recent progress in cryptography has shown that many ideas previously viewed as purely theoretical can sometimes lead to surprisingly efficient implementations. As a particular example, we show how to instantiate the "secure computation in the head" approach of Ishai et al. with a new secure-computation protocol designed in the preprocessing model. After several optimizations, this leads to a communication- and computation-efficient zero-knowledge proof for any "moderately sized" boolean circuit. Our zero-knowledge proof can, in turn, be used to construct digital signature schemes based only on symmetric-key primitives and hence with viable "post-quantum" security. We report on the performance of the resulting schemes, which are currently under consideration by NIST as part of their post-quantum cryptography standardization effort.

Speaker Bio

Jonathan Katz is director of the Maryland Cybersecurity Center and a professor in the Department of Computer Science. He also has a joint appointment in the University of Maryland Institute for Advanced Computer Studies. Katz's research interests lie broadly in the areas of cryptography, computer and network security and complexity theory, with his most recent work focusing on secure multi-party computation, database privacy and the science of cybersecurity. He has co-authored the textbook Introduction to Modern Cryptography (2007), which has been used by colleges and universities throughout the world and published more than 100 scientific articles. He has also done extensive consulting work for U.S. government agencies and private corporations, mostly involving cryptographic protocols and algorithms.