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Author Topic: Guess the Card Game - provably fair and new better odds  (Read 1619 times)
Frz
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November 06, 2013, 11:22:21 PM
 #21

Ok,  now its provable fair as I use my random plus the transaction ID as the seed.  I wont know the transaction ID and you wont know the rand until after so fair to both sides...hehe
This is NOT provably fair. If I send a transaction now you can select a random seed which makes me lose quite easily. This is bad. You don't need to change it for me but don't claim it's provably fair if it's not. Look into what the others are doing. A solution that works for on-chain games like yours is to have a secret of the day that doesn't change and have the SHA-256 (or whatever) hash of that secret known, the secret should be at least 16 bytes so it's hard to find by brute force searching (feel free to use longer secrets). When calculating the result you combine the secret of the day with the transaction id in same way and then find a card from the deck in some way.

For example you could: card = (HMAC_SHA256(secret,txid)/2^256)/52, the result is an index in a deck of 52 cards (note: this uses big integer arithmetic)

After the day is over you publish the secret. Now everyone can verify that the SHA-256 of the secret (which was known to players beforehand) is the same as calculating SHA-256(secret) when the secret is known.

Yes you can screw up implementing provably fair and leak your bet results beforehand but you can also do it correctly and the game becomes provably fair for everyone.

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crudpuppy
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November 07, 2013, 01:24:26 AM
 #22

Ok so I see what your saying since the rand isn't known till after it could be biased which is doubtful but ok. 
So Now you will see sha256 of secret for today posted on home with yesterdays secret(I went with 45 characters don't ask me why that number :-)
so secret+txid though my rand class(posted on about page) will give same card as was drawn during your bid.

That and the fact I've had like 4 bets and 2 won should show me as trustworthy even if it doesn't quite meet provably fair...lol.
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November 07, 2013, 02:47:36 AM
 #23

I don't get how you think a bitcoin gambling website can succeed without being provably fair. But apparently you don't even understand the concept of provable fairness, so I shouldn't be surprised...  Roll Eyes

Maybe a slightly deeper research would have been beneficial to your project?

Monero's privacy and therefore fungibility are MUCH stronger than Bitcoin's. 
This makes Monero a better candidate to deserve the term "digital cash".
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November 07, 2013, 03:29:02 AM
 #24

I don't get how you think a bitcoin gambling website can succeed without being provably fair. But apparently you don't even understand the concept of provable fairness, so I shouldn't be surprised...  Roll Eyes

Maybe a slightly deeper research would have been beneficial to your project?


-erased retort here-

Um pretty sure I've implemented it as said now as my key(seed whatever you wanna call it) is published in hash form and tomorrow will be available in open view for verification and the other part is the tx id which I can't know.  so key+txid = passed to function I published on my site = card drawn for bet.  So nothing is hidden same as your site :-)
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November 07, 2013, 03:31:24 AM
 #25

Oh and please refrain from negative in no way helping feedback.  I have shown I respond to positive feedback so why even bother doing that?
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November 07, 2013, 12:25:23 PM
 #26

Oh and please refrain from negative in no way helping feedback.  I have shown I respond to positive feedback so why even bother doing that?

My message was indeed rather negative only, sorry. I do like your idea, anything different from existing concepts is very valuable. Let's conquer this dice country!

Monero's privacy and therefore fungibility are MUCH stronger than Bitcoin's. 
This makes Monero a better candidate to deserve the term "digital cash".
crudpuppy
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November 08, 2013, 07:01:27 PM
 #27

So any new suggestions?
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November 10, 2013, 01:48:32 AM
 #28

Hmmm the lack of any bids and responses now makes me wonder if I should bother with the guess the card value and guess the exact card modes?  Guess I could look into advertising more...hmmm
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