This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
In the last few years, universally composable (UC) security, defined and extensively investigated by Ran Canetti, has become a popular and important topic in modern cryptography. Canetti's notion has enormous appeal, promising a unified framework under which one can define virtually any cryptographic protocol goal, and further promising that the resulting definitions will be composable in the sense that a protocol solution for some goal will comprise a suitable primitive to use within any other protocol that desires its abstracted functionality. But UC goals are definitionally complex--in fact, the definitions can take tens of pages of English prose to simply write down, and, even then, significant ambiguities may remain.
In this project, Dr. Phillip Rogaway explores an alternative descriptive language for specifying UC goals. Instead of describing the execution model in English, it will be described within the framework of code-based game-playing. Under this descriptive language, a UC definition will be described using a program, the program setting variables that induce a clear and precise notion of adversarial advantage.
Dr. Rogaway will demonstrate the feasibility and practical value of his approach by applying it to universally composable signature schemes. This will be an important first step towards making unambiguous and verifiable UC definitions accessible to the general cryptographic community and those they serve.
