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Topic: Cryptography poker

The question arose. Whether probably to implement gambling poker () so that it was possible to provide security blanket (clear business, cryptography) process of game from a juggling and ?
It is given:
1. The game server - the game server application
2. Players (from 2-10) - application of the game client
Conditions:
1. Players receive on 2 cards from  the reshuffled pack
2. On desktop gives all the best from 3 to 5 cards from the same pack
3. Neither the server, nor other players cannot know or though somehow to calculate what cards at other players, before the game termination
4. Neither the server, nor other players should not know, what cards are selected from a pack, except laid out on desktop
5. Distribution of cards is conducted from one pack so that players did not appear two peak ases
6. Any player cannot, using ignorance of other players, to change the cards to the wished
Poker implementation, namely possible algorithms interests was not specific.
There are ideas? smile

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Re: Cryptography poker

Each player has constant pair of keys. Closed lies on the server and it is not known to other players, opened - only at the specific player, in the course of game in any way on a network do not chase.
At the game beginning each player generates to itself temporal pair of keys. Private keys are sent between players, on the server do not go. It is used for a data interchange between players that the server intercepted nothing.
The server generates a pack and each card protects the sign-code signature.
The server sends a pack, we admit to the player No 1 - 1. It reshuffles a pack and delivers other players (ciphering temporal keys).
Each player accordingly rechecks that with a pack all is normal (the sign-code signature on a place, a dial-up of cards correct) and ciphers its keys of each of players.
The received dial-up of the ciphered cards is sent by each player on the server.
I.e. each player sends on the server a label in which the line is a card, and a column - an encryption of a card a key of the appropriate player.
The server rechecks that all players sent identical labels and anybody changed nothing.
Once again shuffles a pack. For sending to the specific player the card is in addition ciphered by an appropriate constant key. Accordingly closed cards are decrypted by the player in two stages: at first a constant key, and then - temporal.
Open cards go as there are also players them decrypt only the temporal keys.
When the player is opened, the server delivers encryptions of these cards available for it to other players, those decrypt the keys and check that substitution was not also to the player really this card came from the server.

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Re: Cryptography poker

hVostt;
Well, as a variant:
2 packs: one on the server - with cards of the players, the second at players - with nominals of cards.
Players in coordination generate a dial-up of cards [ID-> a card] in any image and exchange it among themselves. All used ID go on the server (without nominals). The server collects a pack from 54 (or how many there cards) ID, shuffles it and distributes cards to players, the part of cards spreads on desktop. Thus players know the cards, but do not know a card on desktop or cards of other players, and the server knows all cards, but does not know their nominals.
Further there is a game as usual. When all rates ended also all are opened - all players send the packs (the identical!) on the server, it checks them among themselves and with the data about distribution, builds a deal with nominals and delivers its players. Players check a deal with the cards and confirm it.
The round is completed.

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Re: Cryptography poker

alekcvp wrote:

Thus players know the cards, but do not know a card on desktop or cards of other players

Thus players know the cards and cards on desktop, but not cards of other players, certainly.

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Re: Cryptography poker

hVostt wrote:

1. Players receive on 2 cards from  the reshuffled pack
2. On desktop gives all the best from 3 to 5 cards from the same pack
3. Neither the server, nor other players cannot know or though somehow to calculate what cards at other players, before the game termination
4. Neither the server, nor other players should not know, what cards are selected from a pack, except laid out on desktop

With a pack the game server works, therefore, anyway, players should be trusted the server. [quote =] 5. Distribution of cards is conducted from one pack so that players did not appear two peak ases

the Jamb which do not presume to itself neither the fair server, nor roguish. We neglect possibility such  from server side. [quote =] 6. Any player cannot, using ignorance of other players, to change the cards on wished

the Trivial digital signature of distributions by the server.
It is necessary to understand clearly that no "Internet circuit" is protected from leaks on on side channels.
It - game on one hand. Thus, the server too should be trusted players.