The Notion of Security for Probabilistic Public-key Cryptosystems

Abstract

The purpose of a cryptosystem is to allow people to communicate securely over an open channel. Before one can discuss whether a cryptosystem meets this goal, however, one must first rigorously define what is meant by security. Three very different formal definitions of security for public-key cryptosystems have been proposed-two by Goldwasser and Micali and one by Yao. In this thesis, it is shown that the three definitions are essentially equivalent.