Using Task-Structured Probabilistic I/O Automata to Analyze an Oblivious Transfer Protocol

Abstract

The Probabilistic I/O Automata framework of Lynch, Segala and Vaandrager provides tools for precisely specifying protocols and reasoning about theircorrectness using multiple levels of abstraction, based on implementation relationships between these levels. We enhance this framework to allow analyzingprotocols that use cryptographic primitives. This requires resolving andreconciling issues such as nondeterministic behavior and scheduling, randomness,resource-bounded computation, and computational hardness assumptions. The enhanced framework allows for more rigorous and systematic analysis of cryptographic protocols. To demonstrate the use of this framework, we present an example analysis that we have done for an Oblivious Transfer protocol.