International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Games and the Impossibility of Realizable Ideal Functionality

Anupam Datta
Ante Derek
John C. Mitchell
Ajith Ramanathan
Andre Scedrov
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Abstract: A cryptographic primitive or a security mechanism can be specified in a variety of ways, such as a condition involving a game against an attacker, construction of an ideal functionality, or a list of properties that must hold in the face of attack. While game conditions are widely used, an ideal functionality is appealing because a mechanism that is indistinguishable from an ideal functionality is therefore guaranteed secure in any larger system that uses it. We relate ideal functionalities to games by defining the \textit{set} of ideal functionalities associated with a game condition and show that under this definition, which reflects accepted use and known examples, bit commitment, a form of group signatures, and some other cryptographic concepts do not have any realizable ideal functionality.
  title={Games and the Impossibility of Realizable Ideal Functionality},
  booktitle={IACR Eprint archive},
  keywords={foundations / universaly composability, bit commitment, group signatures, symmetric encryption},
  note={Third Theory of Cryptography Conference, TCC 2006, Proceedings 13217 received 5 Jul 2005, last revised 9 Mar 2006},
  author={Anupam Datta and Ante Derek and John C. Mitchell and Ajith Ramanathan and Andre Scedrov},