This book constitutes the refereed proceedings of the Sixth Theory of Cryptography Conference
TCC 2009 held in San Francisco CA USA March 15-17 2009. The 33 revised full papers
presented together with two invited talks were carefully reviewed and selected from 109
submissions. The papers are organized in 10 sessions dealing with the paradigms approaches and
techniques used to conceptualize define and provide solutions to natural cryptographic
problems.
