LibTMCG is a C++ library for creating secure and fair online card
games. The library contains a sort of useful classes, algorithms,
and high-level protocols to support an application programmer in
writing such software. The most remarkable feature is the absence
of a trusted third party (TTP), i.e. neither a central game server
nor trusted hardware components are necessary. Thus, with the present
library there is no need for an independent referee, because the
applied protocols provide a basic level of confidentiality and
fairness by itself. Consequently, the library is well-suited for
peer-to-peer (P2P) environments where no TTP is available. Of
course, we cannot avoid that malicious players share information
about their private cards, but the protocols ensure that the shuffle
of the deck is performed randomly (presumed that at least one player
is honest) and thus the cards will be distributed uniformly among
the players. Further, no coalition can learn the private cards of a
player against his will (except for trivial conclusions). The
corresponding cryptographic problem, actually called Mental Poker, has
been studied since 1979 (Shamir, Rivest, and Adleman) by many authors.
LibTMCG provides the first practical implementation of such protocols.

The implementation relies on advanced cryptographic techniques---the
so-called zero-knowledge proofs. Using these building blocks the high
level protocols minimize the effect of coalitions and preserve the
confidentiality of the players' strategy, i.e. the players are not
required to reveal their cards at the end of the game to show that
they did not cheat.