Is it possible to play card games without a deck of cards and without a referee? The question has profound implications for cryptography, in which the need to nominate and monitor a trusted third party (the referee in a cryptographic transaction) is a major pain in the ass — this is the basis for the assertion that Trusted Computing systems will enable P2P games and distributed computation projects to proceed without cheating. This paper demonstrates some of the ways that we can dispense with a referee and rely on math to keep everyone honest.
Mental card games are played without a trusted party and without
cards. It is well known
that the problem of mental card games can be solved in principle. But
the schemes known so
far are too messy to be used in practice. Only for the mental poker
game a suitable solution
is known [Cr’ep 87] that achieves security against player coalition
and complete confidentiality
of a player’s strategy. Here, we present a general-purpose scheme
that may be used as basic
toolbox for straight-forward implementations of card games.
We present a data structure for cards and decks that is secure
against player coalitions
and enables standard operations like picking up a card, opening it,
and (re-)mixing stacks.
Futhermore, we introduce tools for special operations like inserting
a card into the deck,
splitting the deck, parting the game. The correctness of all
operations is testified by zeroknowledge
proofs.
(via Hack the Planet)