bitZino - Bitcoin Casino - Blackjack, Roulette, 3 Card Poker, Slots and more!

[IveBeenBit]

Great work, getting covered in the Forbes blog!

One thing I'd really like to see would be a video screencast on youtube or whatever that walks people like me who are "cryptographically challenged" through your "provably fair" system. You should target it for an audience that is intelligent, yet not specifically trained in high-level math or cryptographic theory. This would be a good step in marketing to traditional online gaming customers and may bring more people into the world of bitcoin.

[dooglus]

Great work, getting covered in the Forbes blog!

That's the first I heard of it.  I googled for it and found the article:
http://www.forbes.com/sites/jonmatonis/2012/08/31/bitzino-and-the-dawn-of-provably-fair-casino-gaming/

One thing I'd really like to see would be a video screencast on youtube or whatever that walks people like me who are "cryptographically challenged" through your "provably fair" system. You should target it for an audience that is intelligent, yet not specifically trained in high-level math or cryptographic theory. This would be a good step in marketing to traditional online gaming customers and may bring more people into the world of bitcoin.

Did you read https://bitzino.com/about/fair ?  If so, is there something in it that's hard to understand?  Or is it just that you prefer to watch video than to read?  Or are you getting hung up on issues like "what is a hash"?

https://techblog.bitzino.com/2012-06-30-provably-fair-shuffling-through-cryptography.html goes into more detail, but I don't know if that's just going to confuse you more, since I've no idea what bit you're having trouble with.

[IveBeenBit]

Did you read https://bitzino.com/about/fair ?  If so, is there something in it that's hard to understand?  Or is it just that you prefer to watch video than to read?  Or are you getting hung up on issues like "what is a hash"?

I have errands to run, so this will be a quick reply, but I did not find that helpful. Troublesome parts, with my responses:

Our servers also generate a random string, called the server_seed. We combine the initial_shuffle and the server_seed strings into a single JSON encoded string. We call this JSON string the secret.

Response: "WTF is a JSON string?"

Finally, we hash the secret using the SHA256 one-way hashing algorithm. This is called the Hash(secret). We show you this value to you before the hand starts, so you can independently verify that we didn't manipulate the server_seed or the initial_shuffle.

Response: This I understand, but only because a few months ago a bitcoin/cryptogeek friend of mine explained what a SHA256 is and how it worked to verify the bitcoin kamikaze game, if you remember that one. Without that lesson, this would make no sense to me.

Our servers then hash the combination of the server_seed and the client_seed (using SHA256 again). We use this hash to seed the Mersenne Twister pseudorandom number generator. We then fully reshuffle the deck using this random number generator

Response: "Huh? Seed? Mersene Twisters?"

Anyways, even if I personally were to understand it, it would be valuable to explain it so normal people understood. Sort of like how my friend taught me how Bitcoin Kamikaze was provably fair as well. This may entice more traditional online gaming aficionados to adopt Bitcoin, thus bolstering our economy.

For instance, the Wizard of Odds runs a popular gambling forum. He endorses Bodog gaming because he says that there have been too many sites that were rigged and he trusts Bodog (plus he probably makes a bunch on affiliate deals, but that's neither here nor there). If Bitzino can explain to normal people how their games are "provably fair" via mathematics, then their system should carry as much weight as a Wizard endorsement, if not more so.

[ErebusBat]

I think those are very good points.  Non-geeks have no idea, and it really doesn't matter, about JSON or SHA256 specifics.

[dooglus]

Our servers also generate a random string, called the server_seed. We combine the initial_shuffle and the server_seed strings into a single JSON encoded string. We call this JSON string the secret.

Response: "WTF is a JSON string?"

"JSON, or JavaScript Object Notation, is a text-based open standard designed for human-readable data interchange" -- http://en.wikipedia.org/wiki/JSON

It's just a way of formatting strings.  Since the server has two things it wants to keep secret, but doesn't want to flood you with too much information, it combines the two things into a single string of text before hashing it.  JSON is just a convenient way of doing it.  So if the server_seed is "xxx1" and the initial_shuffle is "yyy2", the secret formed by combining these two pieces of information would be:

{"server_seed":"xxx1","initial_shuffle":"yyy2"}

and that's what ends up getting hashed and displayed before the game starts.

Finally, we hash the secret using the SHA256 one-way hashing algorithm. This is called the Hash(secret). We show you this value to you before the hand starts, so you can independently verify that we didn't manipulate the server_seed or the initial_shuffle.

Response: This I understand, but only because a few months ago a bitcoin/cryptogeek friend of mine explained what a SHA256 is and how it worked to verify the bitcoin kamikaze game, if you remember that one. Without that lesson, this would make no sense to me.

That's the part I guessed would be a stumbling block.

Our servers then hash the combination of the server_seed and the client_seed (using SHA256 again). We use this hash to seed the Mersenne Twister pseudorandom number generator. We then fully reshuffle the deck using this random number generator

Response: "Huh? Seed? Mersene Twisters?"

Mersenne Twister is an algorithm for shuffling a list into an apparently random order.  It's not really random; it takes a list that you want shuffled and a number (called the seed) that determines how the shuffle will happen, exactly.  If you always use the same seed, you'll always get the same shuffle, but use a slightly different seed and you'll get a completely different shuffle.  It's a little like hashing in that respect.

Anyways, even if I personally were to understand it, it would be valuable to explain it so normal people understood. Sort of like how my friend taught me how Bitcoin Kamikaze was provably fair as well. This may entice more traditional online gaming aficionados to adopt Bitcoin, thus bolstering our economy.

For instance, the Wizard of Odds runs a popular gambling forum. He endorses Bodog gaming because he says that there have been too many sites that were rigged and he trusts Bodog (plus he probably makes a bunch on affiliate deals, but that's neither here nor there). If Bitzino can explain to normal people how their games are "provably fair" via mathematics, then their system should carry as much weight as a Wizard endorsement, if not more so.

Understood.  I guess it's hard to know how far back to basics to go when giving such an explanation.  I notice Mersenne Twister is linked to a page that explains it, but SHA256 isn't, for example.  I've gone through the process of explaining all this to someone with no relevant knowledge myself, and it can take a while to get through to them, even when you have immediate feedback of which bits they're struggling with.

I think those are very good points.  Non-geeks have no idea, and it really doesn't matter, about JSON or SHA256 specifics.

So I guess a separate explanation for 'non-geeks' would be useful.  The specifics are important, otherwise there's no point in having it "provably fair".  The method used needs to be explained fully enough that though who care and technically able can go through the motions themselves and verify a few hands.

[libertaad]

It is ErebusBat, I just never setup an account before because BJ isn't my game.   Account setup and deposit made... look for 'donations' this weekend

Welcome to the site! I sent you a quarter BTC to thank you for all the feedback you've been providing

Very nice! I was able to get my 0.005 deposit back and then some! Will definitely come back  

Oh, and made 2 withdrawals, one took > 20 mins, the other was within seconds. Thanks!

Cool, glad you like it! Our system typically sends withdrawals instantly. The main reason for a short delay is if you have unconfirmed transactions. We require 2 confirmations on all your deposits before sending the withdrawal.

Tried it out on my lunch break.  A+! Using mouse to play the inside is easier.  And I like the double all wagers option.  Amazing quick response time!

You never committed on my android app comment.  Doesn't HTML5 have features that make that transference easier?

Nice, I'm glad the UI improvements helped

HTML5 is great, because it typically just works on mobile web browsers. We do make sure to test out everything on mobile browsers as well, just to make sure it's all working well. We may eventually do native apps in the future, but for now we are just focusing on a good HTML5 experience.

Also you need a 'half bets' with that double bet buttons

Good point. We want to make sure not to make the interface too cluttered, but this would probably be useful.

Great work, getting covered in the Forbes blog!

One thing I'd really like to see would be a video screencast on youtube or whatever that walks people like me who are "cryptographically challenged" through your "provably fair" system. You should target it for an audience that is intelligent, yet not specifically trained in high-level math or cryptographic theory. This would be a good step in marketing to traditional online gaming customers and may bring more people into the world of bitcoin.

Thanks! This is really exciting. Our first major news coverage!

Thanks as well for the feedback on what you find difficult to understand about the provably fair system. I am definitely aware the education around this is one of our bigger hurdles here, so hearing directly from you what concepts you don't understand is definitely very helpful!

We tried to provide a simple explanation on our website, and a more in-depth explanation on our tech blog, but perhaps our simple explanation isn't simple enough. We'll definitely take your suggestions, and probably rewrite parts of the "simple" explanation.

[ErebusBat]

It is ErebusBat, I just never setup an account before because BJ isn't my game.   Account setup and deposit made... look for 'donations' this weekend

Welcome to the site! I sent you a quarter BTC to thank you for all the feedback you've been providing

Received thanks!  I will give it back shortly

[IveBeenBit]

Dooglus, thanks for the explanation. I found it very helpful.

[TTBit]

Request: 3 card poker. Surprised I am the first.

[ErebusBat]

Request: 3 card poker. Surprised I am the first.

I don't think you are.  But +1

[libertaad]

We've just pushed another round of changes. These are mostly minor, but I wanted to confirm all the issues you brought up that were addressed:

- The homepage now always goes to the previously played game.
- We handle internet failure more gracefully, by adding a timeout to our ajax calls and displaying an alert.
- Fixed the slightly wonky layout of the Roulette table in Chromium (that was due to CSS rounding issues)

Request: 3 card poker. Surprised I am the first.

Sounds good! We've already made some progress here, because we were working on Let it Ride, and were considering adding the 3 card poker bets to it. We're focusing on adding craps next, but we'll work on 3 card poker after that!

[ChupacabraHunter]

This may be a bit "back to basics" for this thread, but I am going to give it a shot,and see what responses I get:

I am trying to TEST/SHOW bitZino to be Provably Fair to myself and a friend.

So, without programming, and using available third-party (online) tools, how can I CHECK the sequence of shuffles, and how they get manipulated by the player's secret re-hashing (cutting) of the deck.

Is this even possible?

---------------------
I saw the python script, but I cannot run that

I am thinking along the lines of taking your first shuffle, hashing it somewhere like:

http://www.movable-type.co.uk/scripts/sha256.html

getting a hash result which I (myself) manually or using some other tool like excel or something to do whatever it is that you do to "cut" the deck... and then finding the sequence of cards that you dealt, and had the same SHA256 hash as what is shown as "proof"

And then, I would like to hash the final sequence using the above site, or some other one that is not connected to you, but I can easily access without programming.

-----------------------

I hope this is not too complicated.  I just want to be able to walk-through, and VERIFY that which you claim is "Provably Fair"

-----------------------
I do believe you, but can you also show me how I can do the checking MYSELF!? Thanks. 

[libertaad]

This may be a bit "back to basics" for this thread, but I am going to give it a shot,and see what responses I get:

I am trying to TEST/SHOW bitZino to be Provably Fair to myself and a friend.

So, without programming, and using available third-party (online) tools, how can I CHECK the sequence of shuffles, and how they get manipulated by the player's secret re-hashing (cutting) of the deck.

Is this even possible?

-----------------------

I hope this is not too complicated.  I just want to be able to walk-through, and VERIFY that which you claim is "Provably Fair"

This is a great idea! As you mentioned, Dooglus did write a python script which verifies the secret and outputs the final shuffle of the deck given the Hash(secret), secret and the client_seed. Additionally, we have a javascript hand verifier located at https://bitzino.com/about/fair. If you are inclined to take a deeper look at the code for our verifier, you can view the source of that page and see the javascript verifier - it's just 100 lines of well-commented code.

However, I understand that you may want to verify on your own without relying on having coding expertise or relying on code that is hosted on our own website. To that end, I've outlined the steps to do this below: (unfortunately, there will be just a little bit of "coding", but it's really just copying and pasting certain commands into a javascript console. This is necessary because there isn't an online implementation that I could find of the Fisher-Yates shuffle algorithm)

Step 1: Verify the Hash(secret) is derived from the secret

After playing a hand of any game at bitzino, go to http://www.movable-type.co.uk/scripts/sha256.html, and copy and paste the Secret in to the box. Click on the "Generate Hash" button, and verify that the hash generated on that website matches the Hash(secret) you see on bitzino.

Step 2: Generate the seed from the client_seed and the server_seed

While still on the same website, copy and paste the client_seed into the box, followed directly by the server_seed (the server_seed is part of the Secret). E.g, if the client_seed is "ABC", and the server seed is "123", the box should have "ABC123" in it. (Also, make sure you're copying the client_seed from "Last hand" on bitZino, not from the "Next hand"). Click on the "Generate Hash" button. Now, keep this page open, because we will be using this Hash later.

Step 3: Set up a javascript console with the Mersenne Twister function

Go to http://jsconsole.com. This is a javascript console, and it's where we'll be completing all of the following steps.

Copy and paste all of the code from https://bitzino.com/static/MersenneTwister19937.js into the javascript console. This will initialize the Mersenne Twister function which will be used later on.

If you'd like to verify that the above code is indeed a pristine copy of the Mersenne Twister, you can download the original zip file from http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/VERSIONS/JAVASCRIPT/java-script.html

Step 4: Seed the random number generator

Type the following commands into the jsconsole:

Code:

var seedString = "<hash value from step 2>";
var seed = parseInt(seedString.substring(seedString.length - 8), 16);
var mt = new MersenneTwister19937();
mt.init_genrand(seed);

Note that the first line of code isn't actually <hash value from step 2>, you should replace that part with the value you got from step 2.

Step 5: Set up the initial_shuffle

Create a variable in the jsconsole that is equal to the initial_shuffle from bitzino. (The initial_shuffle is part of the Secret).

Code:

var initialShuffle = "<initial_shuffle>";

Step 6: Reshuffle the deck using the Mersenne Twister RNG, and the Fisher-Yates shuffling algorithm

Copy this code into the jsconsole:

Code:

function shuffle(deck_string, mt) {
    var tmp, new_deck = deck_string.split('');
    for(var i = new_deck.length - 1; i > 0; i--) {
      r = mt.genrand_int32() % (i + 1);
      tmp = new_deck[r];
      new_deck[r] = new_deck[i];
      new_deck[i] = tmp;
    }
    return new_deck.join('');
 }

shuffle(initialShuffle, mt);

At this point, the jsconsole will spit out a value that should be identical to bitZino's final_shuffle.

Final thoughts

I really wish there were an online Fisher-Yates/Mersenne Twister card shuffler, so that every step in this process would be as easy as step 1. If anyone does know of one, please let me know so that I can make this process easier! I also recognize that you are still depending on a lot of code that is just copied directly from me, but I think the fact that it's posted here publicly should show that it is honest, and does what it says it does.

I hope this helps!

[dooglus]

Here's a blog post mentioning bitZino:

  http://calvinayre.com/2012/09/03/business/bitzino-touts-provably-fair-games-but-can-bitcoin-only-casinos-succeed/

[ChupacabraHunter]

This may be a bit "back to basics" for this thread, but I am going to give it a shot,and see what responses I get:

I am trying to TEST/SHOW bitZino to be Provably Fair to myself and a friend.

So, without programming, and using available third-party (online) tools, how can I CHECK the sequence of shuffles, and how they get manipulated by the player's secret re-hashing (cutting) of the deck.

Is this even possible?

-----------------------

I hope this is not too complicated.  I just want to be able to walk-through, and VERIFY that which you claim is "Provably Fair"

This is a great idea! As you mentioned, Dooglus did write a python script which verifies the secret and outputs the final shuffle of the deck given the Hash(secret), secret and the client_seed. Additionally, we have a javascript hand verifier located at https://bitzino.com/about/fair. If you are inclined to take a deeper look at the code for our verifier, you can view the source of that page and see the javascript verifier - it's just 100 lines of well-commented code.

However, I understand that you may want to verify on your own without relying on having coding expertise or relying on code that is hosted on our own website. To that end, I've outlined the steps to do this below: (unfortunately, there will be just a little bit of "coding", but it's really just copying and pasting certain commands into a javascript console. This is necessary because there isn't an online implementation that I could find of the Fisher-Yates shuffle algorithm)

Step 1: Verify the Hash(secret) is derived from the secret

After playing a hand of any game at bitzino, go to http://www.movable-type.co.uk/scripts/sha256.html, and copy and paste the Secret in to the box. Click on the "Generate Hash" button, and verify that the hash generated on that website matches the Hash(secret) you see on bitzino.

Step 2: Generate the seed from the client_seed and the server_seed

While still on the same website, copy and paste the client_seed into the box, followed directly by the server_seed (the server_seed is part of the Secret). E.g, if the client_seed is "ABC", and the server seed is "123", the box should have "ABC123" in it. (Also, make sure you're copying the client_seed from "Last hand" on bitZino, not from the "Next hand"). Click on the "Generate Hash" button. Now, keep this page open, because we will be using this Hash later.

Step 3: Set up a javascript console with the Mersenne Twister function

Go to http://jsconsole.com. This is a javascript console, and it's where we'll be completing all of the following steps.

Copy and paste all of the code from https://bitzino.com/static/MersenneTwister19937.js into the javascript console. This will initialize the Mersenne Twister function which will be used later on.

If you'd like to verify that the above code is indeed a pristine copy of the Mersenne Twister, you can download the original zip file from http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/VERSIONS/JAVASCRIPT/java-script.html

Step 4: Seed the random number generator

Type the following commands into the jsconsole:

Code:

var seedString = "<hash value from step 2>";
var seed = parseInt(seedString.substring(seedString.length - 8), 16);
var mt = new MersenneTwister19937();
mt.init_genrand(seed);

Note that the first line of code isn't actually <hash value from step 2>, you should replace that part with the value you got from step 2.

Step 5: Set up the initial_shuffle

Create a variable in the jsconsole that is equal to the initial_shuffle from bitzino. (The initial_shuffle is part of the Secret).

Code:

var initialShuffle = "<initial_shuffle>";

Step 6: Reshuffle the deck using the Mersenne Twister RNG, and the Fisher-Yates shuffling algorithm

Copy this code into the jsconsole:

Code:

function shuffle(deck_string, mt) {
    var tmp, new_deck = deck_string.split('');
    for(var i = new_deck.length - 1; i > 0; i--) {
      r = mt.genrand_int32() % (i + 1);
      tmp = new_deck[r];
      new_deck[r] = new_deck[i];
      new_deck[i] = tmp;
    }
    return new_deck.join('');
 }

shuffle(initialShuffle, mt);

At this point, the jsconsole will spit out a value that should be identical to bitZino's final_shuffle.

Final thoughts

I really wish there were an online Fisher-Yates/Mersenne Twister card shuffler, so that every step in this process would be as easy as step 1. If anyone

does know of one, please let me know so that I can make this process easier! I also recognize that you are still depending on a lot of code that is just copied directly from me, but I think the fact that it
's posted here publicly should show that it is honest, and does what it says it does.

I hope this helps!

Thanks  so much, this is EXACTLY   what I/we were  looking for!

You have officially SILENCED  my sceptic friend!  Peace and quiet at last!! Good Luck making great   waves in the gambling word...and please do be careful with your  COLD STORED COINS!!!

[dooglus]

Thanks  so much, this is EXACTLY   what I/we were  looking for!

You have officially SILENCED  my sceptic friend!  Peace and quiet at last!! Good Luck making great   waves in the gambling word...and please do be careful with your  COLD STORED COINS!!!

Would it have helped if there was a site which walked you through the process step by step?  I'm thinking of making such a thing.  Something more automatic than having to visit all those different sites to do it manually, but less automatic than the site bitZino provides which shows a few progress bars and says "yep, it's fine".

I'm not sure if that would be useful.  Maybe it's more convincing for people like your friend to go through the steps "manually" for themselves.

Either way, having a neutral 3rd party like myself provide a verification site is likely more convincing than having bitZino verify their own data...

[IveBeenBit]

Dooglus - I for one would appreciate such a site. If you refer to my post a few above this one, one of the ways that I really "got" what a SHA256 function did was when I went to an online calculator and hashed a few text strings. I'd do things like enter a lengthy string and then make a minor change, like changing 1 letter from upper to lowercase, or adding a space at the end and comparing the resulting hashes. So that was my learning process for the utility of Sha256.

That said, if you say Bitzino's system is legit, that's good enough for me to play there, though I'd still visit a site like you described just because I like learning stuff and experimenting.

[dooglus]

That said, if you say Bitzino's system is legit, that's good enough for me to play there, though I'd still visit a site like you described just because I like learning stuff and experimenting.

I've verified a few of the hands I've played, and they've all checked out.  I can't say they're all legit without checking them all, but I have a good feeling about the site.  I'm about 7 BTC down overall I think.

[speeder]

How often you reshuffle and how many decks you use on Blackjack?

The rules does not state it!!!

[dooglus]

How often you reshuffle and how many decks you use on Blackjack?

The rules does not state it!!!

They use 8 decks and shuffle before every hand.

You can see that 8 decks are used by opening up the 'provably fair' sub-window and counting the length of the "final shuffle" string.  Reading the "what is this?" link in the bottom right corner of that sub-window makes it clear that they shuffle before dealing every hand.