Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [mental-poker]

Mental poker is the common description for a set of cryptographic problems related to playing a fair game over a distance without the need for any trusted third party.

Mental poker is the common description for a set of cryptographic problems related to playing a fair game over a distance without the need for any trusted third party.

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Is there a mental poker algorithm that does not rely on commutative encryption?

The algorithm for mental poker that I saw on Wikipedia and everywhere else relies on an encryption algorithm such that $E_k(E_j(P)) = E_j(E_k(P))$, but I can't find a modern and secure algorithm for which this is true. The only algorithm I found…
Daffy
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Cryptographic system with double keys with reversible order

While reading Shamir, Rivest and Adleman's paper on "Mental Poker", I've met a mention of system such that $E_a(E_b(x)) = E_b(E_a(x))$, without however disclosing details on it, with $E_a(x)$ being “encrypt plaintext $x$ with key $a$”. Do any…
toriningen
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Is there a public key semantically secure cryptosystem for which one can prove in zero knowledge the equivalence of two plaintexts?

If Alice encrypts two messages $a$ and $b$, such that $x=E(a)$, $y=E(b)$. Can Alice prove (without revealing $a$, $b$ or the private key) that $a = b$? Obviously the proof must not be too long and it should be practical to compute and verify (either…
SDL
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Murder Mystery Party

For a "Murder Mystery Party", one person is chosen anonymously to be the murderer (i.e., only the murderer knows who the murderer is) by shuffling cards with everyone randomly taking a private card (one card has "You Are The Murderer!" written on…
bobuhito
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Relaxed trust criterion for mental poker server?

I've read a lot about protocols for mental poker without a trusted server, but I'm interested in the possibility of a faster, more practical protocol that relaxes that criterion a bit and "trusts" a third-party server whose trustworthiness can be…
Lee Daniel Crocker
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Mental Poker with untrusted server (i.e. no peer to peer)

The question of implementing peer to peer mental poker has already been asked on stackoverflow. And there appears to be an implementation called LibTMCG. Also on this site a question was asked about problems such as clients disconnecting or refusing…
user782220
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Is there a cryptographic way (a la mental poker) two people can determine if they both Like each other, without revealing their personal preferences?

Specifically: Alice and Bob want to know if they like each other, but won't admit it if the other person doesn't reciprocate. (They're teenagers, or physicists.) They don't trust anyone else, so want to do it cryptographically. So, say A->B=1 if…
doctorofphysics
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Faster Shuffling for a Simple Application

Alice, Bob, and Charlie are working on three projects. Alice is the manager. At the beginning of each day, she chooses one project to work on (this choice is based on her preferences and is not random) and then assigns the other projects to Bob and…
bobuhito
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Understanding ElGamal encryption for a Mental Poker Case

I am looking to understand ElGamal encryption as it is used in a specic context described below. I am interested in creating a practical form of Mental Poker for games other than poker developed by Phillip Golle in 2005 found here:…
Mercure
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A question or few about Mental Poker

I have spent some time studying the "Mental Poker" protocol (sometimes called SRA), initially proposed by Shamir, Rivest, and Adleman. Much of the current literature surrounding SRA deals with implementations, most of which seek to address specific…
Cryptozen
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Mental Poker: Kriegspiel tic-tac-toe

The SBMC comic shared rules for a new version of tic-tac-toe today — I'm trying to figure out if there's a mental-poker/zero trustless version which could be played between two untrusting players (without the "monitor"). Is there a way we can know…
JP.
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Can elliptic curve groups be used for commutative encryption?

In trying to implement mental poker, can all players agree on a standard set of 52 points on the curve corresponding to each card, and then to "encrypt" a card you just multiply it by a scalar which is your encryption key? (and to decrypt, multiply…
dspyz
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What is a secure, modern, partially homomorphic encryption scheme?

I was reading this paper by Philippe Golle on using the homomorphic properties of ElGamal encryption to play a game of mental poker (i.e. cryptographically secure poker without a trusted third party dealer). I decided that it would be a good project…
user3450456
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How to play Mental Skull

"Skull" or "Skull and Roses" is a table top game. The rules can be found here. I was thinking of how I could play this game P2P. At first it seemed easy: Each time I had to place a card face down I would make a choice hash it, send it to my…
Julian
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Is it safe to publicly announce the prime number in Shamir three-pass protocol

So say, I want to use a prime number p for anyone that wants to communicate with me using Shamir's Three Pass Protocol. I will be maintaining my secret keypair (encryption exponent, decryption exponent) and will be expecting other parties to create…
zetaprime
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