PBMX is a framework to creating secure and fair games that can be played over mail.
The main concern is supporting games that feature information that is secret, unknown, or unavailable without the need for a trusted third party. Secret information is information known to only a subset of the players; this could be e.g. in a game of poker, the contents of a player's hand. Unknown information is information that no player knows; in a game of poker, the contents of the deck