Few days ago, a member asked about this in Bitcoin Discussion here: Mining process - SHA256 - Probability. I thought it would be better if I create a new thread for the reply I posted for him so more people who don't know the process can read it.

So if you read various beginners' guide on Bitcoin and blockchain on internet then will you surely come across a topic on Proof of Work (PoW) algorithm. Almost of all of them describes PoW as a consensus algorithm where miners try to find a solution to a mathematical puzzle and the first one to get the solution mines the block! So this thread is all about what that 'Mathematical Puzzle' is because the solution of this mathematical puzzle is what known as the hash of the block.

Finding block hash is nothing but finding a value which is less than the target value. Target value is adjusted after every 2,016 blocks. Current target value (as on 22nd August) is:

0x000000000000000000109bac0000000000000000000000000000000000000000 (hexadecimal form)
or
1590739304116800001454600275103718494518067345886281728 (decimal/integer number)


Now in order to find the block hash, you as a miner need to find an integer value less than the above number. But this is not very simple because you need to include 6 values in your computation together known as Block Header:
> Version
> Hash of previous block
> Merkle Root
> Time of mining
> Bits (difficulty in compact form)
> Nonce (an incrementing number)

So the process of mining involves calculating double SHA-256 of these 6 values in such a way that result hexadecimal hash is less than the current target. The whole process is defined here: o_e_l_e_o's reply to this post. Now let's take an example of Block: 644,731 and try to verify the solution provided by the miner:



For block 644,731, we have:
Version = 20400000 (hexadecimal)
Hash of Previous Block = 000000000000000000083d157a8a2a589a74fc2f7b91245cb3a415c23d7cc79a
Merkle Root = 9453cfc708a1cc84f3f36c2bae68202b03ad2866bb02da511d7e603a4e9d1fd1
Time = 16:42:15 as per GMT
Bits = 386,964,396 (decimal)
Nonce = 2035916310 (decimal)



Converting everything in hexadecimal form (little-endian), we will have following value,

0x000040209ac77c3dc215a4b35c24917b2ffc749a582a8a7a153d08000000000000000000d11f9d4e3a607e1d51da02bb6628ad032b2068ae2b6cf3f384cca108c7cf539467f93f5fac9b1017169e5979

(text is colored to differentiate six parameters)



The final step involves performing SHA-256 hashing twice on the above value and the result will be:
811802676f41d6aff67ad767517c466c4c8d3b87c81009000000000000000000



Converting it in big-endian, we have:
0000000000000000000910c8873b8d4c6c467c5167d77af6afd6416f67021881 which will become block hash of the block.



Now you can compare,
Target Value = 0x000000000000000000109bac0000000000000000000000000000000000000000 or 1590739304116800001454600275103718494518067345886281728

Block Hash (644,731) = 0000000000000000000910c8873b8d4c6c467c5167d77af6afd6416f67021881 or 868308124812842907393685749016650546999869456114653313



Since 868308124812842907393685749016650546999869456114653313 is smaller than 1590739304116800001454600275103718494518067345886281728, it is accepted as a correct solution and will become the block hash.

Don't you think shifting Pool joining thread to main 'Gambling' or 'Gambling Discussion' section will put more eyes on that? Is 'Games and Rounds' the most suitable section for that thread?

Nevertheless, Messi is most probably set to join Man City tomorrow. Are we gonna see more participants after that?

Excited for this year's League! It gonna be huge.

You are absolutely right. There is a difference between 'cheating' and 'scamming'. This tool will only verify that the casino is not cheating you by showing manipulated bet results. However, you should take due-diligence before depositing money on a casino because even though casino is provably-fair, it can scam by not paying you or come up with some shitty rule to ban your account.

But wait, btcgosu get that covered too! @efialtis has posted some top-notch reviews of the popular casinos on btcgosu and he's adding new periodically. These reviews can be taken into consideration for the process of due-diligence and picking right casino for you, more here: https://www.btcgosu.com/

You are right about DeFi. Decentralization has both benefits as well as drawbacks. At one side, DeFi allow us to create modelled economic functions like borrowing/lending, market operations, etc and commit the rules to blockchain via smart contracts so they work as defined no matter what. But at the same time, blockchain is heavily abused by spammers/scammers who create good-for-nothing contracts in order to earn quick bucks and there is no way to stop them because blockchain is decentralized.

Same happened to Ethereum chain is 2017-18 when `ICO Boom` over-glorified Ethereum but that didn't end well. We do have some great projects which used ETH ecosystem to create big Business Value (BV) by tokenizing valuable assets or services. One great example is DIGITAL GOLD, the project which has successfully tokenized gold on ethereum blockchain and maintaining par-value with real world gold.

However, problem initiated when people started promising `stars and moon` on-chain and diluted ICO/tokens market. Same is happening with DeFi. YAM token is one great example.

Your wait it over, as I promised on the first page of this thread, btcgosu has already come up with the biggest third-party provably fair verification tool. It is currently covering 25 casinos and 49 games.

Here's the link: https://www.btcgosu.com/tools/provably-fair-verifier/

Can't see the casino or game you were looking for in the tool? No problem, you can request addition of unlisted casinos/games in this thread: https://bitcointalk.org/index.php?topic=5262141.0 and same will get added in the tool in near future.

Long story short, Yahoo once again bettered me. That's I guess 3rd time on SwC and in total 4th time including SportsBet if I am keeping the tally right.
They say Poker is game of wits and that so happened. He completely outclassed me. That flush hit on Turn was damn unlucky for me. By the way @yahoo62278 suppose you didn't get another Hearts on turn, would you call my raise on turn? I guess it was pretty simple to deduce that I was playing on 'three of a kind Ace' or 'Pocket Aces'. What would have been your call in that situation?

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So finally it was the end to my long standing belief that I always win if I borrow the entry fees. LoL!

Oh! You still need to upgrade your detective skills. 0.01 BTC is for Runner's Up tournament so prizes are same. 0.05 BTC for Championship and 0.01 for Losers.

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Any guesses, who gonna end up in ITM today? YES! THAT'S ME. Any guesses why?

Can anyone send me 1400 chips for this week? I am out of chips on SwC.

You are seriously under-estimating the intensity of the issue. I have spent 7 months as a part of the Crypto Casino Development team. We had spent quite a time in studying various simulation techniques which could be used to harness the results in the favor of casino in long run.

As we all know, humans are worst random generators. In long run, they tend to exhibit same pattern. Consider a typical gambler, if he plays Dice game daily, he is surely following a specific strategy. Casino will set a threshold, let say, 50K bets. Over 50K bets, casino only need to gather certain information about player's betting strategy such as how many times does he like to roll above 50 or below 50 (it can be any number depending on player's stategy) in single auto-betting session, how often does he change the pair of seeds. Just studying such details, casino can set a script for a particular player.

If (player ID === N) { show hash of the server seed which when used with player's selected client seed generates result in favor of casino as per player's previous betting strategy with nonce from 0/1 to S in 55%+ cases }

where S = average number of bets player makes in between changing seeds.
If S is a number less than 5000 then even simple GPU laptop can generate such rigged server seed in less than a second as per the manipulated script. Just imagine, this small tweak will increase the house edge to 10+ percent!!

Ok! Nice question! Being an Economics enthusiast, I have surely given thought to that in past. I have come up with a revolutionary although quite complicated idea. I have named it 'Weighted Layer Classification of Money'.

So under current Debt based economy, money can be generated out of thin air due to the working of 'money multiplier'. By keeping X amount in reserves, banks can further lend the money they received as deposits. This process continues till (1/reserve rate) rounds. In the end, if reserve rate is 10%, for every $100 there will be 100 * (1/10%) = $1000 money in the economy. It leads to inflation, fall in PPP, ever-increasing debts, high rates of interests and many other problems.

Under Weighted Layer Classification of Money, I suggest to have 3 to 5 layers of money. So rather than having one currency in the economy, I suggest to have 3 to 5 different currencies in the economy.

Under 3-Weighted Layers Classification,
-there will be one prime currency, let say, Dollar. The value of this currency will be floating.
-then there will be first secondary currency, let say Follar. The value of this currency will be fixed to 0.80 * Dollar.
-then there will be second secondary currency, let say Gollar. The value of this currency will be fixed to 0.60 * Dollar.

Banks can accept deposits in any of the three currencies. However, lending structure will be as following:

For every 1 Dollar received as deposit, bank can only lend 1 Follar.
For every 1 Follar received as deposit, bank can only lend 1 Gollar.
Banks cannot further lend the Gollars received as deposit.

Interest on Borrowings will be charged in same layer. So if bank lent loan in Follars, it can only charge interest in Follars.
Interest on Deposits will be paid in one-below layer. So if bank accepted deposits in Dollars, it has to pay interest in Follars except for Gollars.

Using this system, there will be a weighted control on how much money can be generated in economy plus borrowing activities can still be performed in economy. We cannot create zero-debt economy because debt is also a backbone of the economy. In the absence of debt structure, many ventures won't able to get launched which will seriously affect economy.

Actually, this is an overview of the model I proposed to a DeFi project which contacted me for a suggestion of a system for their lending/borrowing functionality. I thought this could be a good fit to this thread so I posted here. However, there is lot more technicality involved which I think is out of this thread's scope so I won't discuss.

That was really sad to read but you can't blame Coinbase Pro for your error even 1%. They have no liability to give back your asset since every centralized exchange service clearly mentions that depositing any asset other than the specified will lead to permanent loss of funds. Moreover, addresses  on centralized exchanges are generated by Hierarchical Deterministic (HD) process. There is high chance that the address on which your GOLD tokens are sitting is one of address of Cold Wallet. In order to retrieve your GOLD balance and send that back to you, they have to bring private keys online which could risk the safety of millions of dollars worth of coins lying on other addresses of the branches.

You would probably have a chance if they supported GOLD token because in that case they may have sent you the balance from their hot wallet. But since they don't support GOLD token on their platform, your chances of getting your funds back is next to zero.

Yesterday I sent a personal message to FJ to inquire if the matter is closed from their end so I can make my final statement and whether they wanna stick to the statement that 'they still consider current Dice probably fair even though they are ready to change the implementation in next update'.

To which I got the reply that they are still looking into the additional insights I provided in post number #8528 and will get back to me on 3rd September. Let's see what reply they come up with.

I have a good news for you.

BTCgosu.com is launching a tool this Sunday where users can verify bets for over 30 casinos at single place. With the introduction of this tool, BTCGosu is aiming to become the biggest third-party verifier in Crypto Gambling industry. I am personally managing the built of the tool. BC.Game is one of the 33 casinos which will be launched this Sunday.

I will surely include LuckyFish in next update. Keep an eye on BTCGosu thread or this thread this weekend when tool will be announced.

-webtricks

Thanks @tokeweed. I appreciate your words.

Okay! Since you mentioned Random Number Generator (RNG) and Certification by ITech Labs, I should explain how RNG and Provably Fair system are two different concepts and contribute differently to the Fairness.

What is Random Number Generator (RNG)?

RNG algorithm is used to make sure that the results are:

• unpredictable
• non-repeatable
• uniformly distributed

Casino decides a starting seed which in unknown to the public. Then uses popular hashing algorithm like SHA-1, SHA-2 to generate hashes for the successive rounds of betting. It is more of a precautionary step for Casino (host) than for Player. If results are based on RNG, casino can make sure that players don't anticipate the pattern of result generation by studying large number of bets because every bet is unpredictable, non-repeatable and uniformly distributed than the previous one. However, RNG Certificate doesn't prove that Casino is following the RNG Algorithm too because it is no way possible for player to verify the process of seed generation since it is done in back-end.

In order to involve player in the result generation process and ensure that player can verify the results, Provably Fair Algorithm is followed.

Now I am citing the text from the whitepaper of Crypto Gambling Foundation:

Source: https://cryptogambling.org/whitepapers/provably-fair-algorithms.pdf

Ok! Now I want you guys to read the above text at least 2 times and then decide if current implementation of FortuneJack is Provably Fair or not.

What is Crypto Gambling Foundation?


There are several reputable casinos which have verified their Provably Fair Script from Crypto Gambling Foundation namely, bustabit, primedice, Stake, cyberdice, rocket.run, bustadice, Crypto.Games, DuckDice, OneHash, BitVest and BC.Game.

You were talking about industry standards, this is Provably Fair Standard and if FortuneJack passes this standard with current implementation, I will keep quiet and won't accept any gift/reward. But I am 100% sure that FortuneJack will fail this standard because hostSeed changes after the change of publicSeed.

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I am not doubting FortuneJack and not accusing you guys of cheating the players. I am fully convinced that you guys are surely following RNG mechanism while computing Server Seeds for the players. But if you guys are claiming that you are Provably Fair too then make sure that you are following the most appropriate standard of Provably Fair. This should be your flow of determining bet result as per Provably Fair System:

Step 1: Generate a server seed using Random Number Generator (RNG) algorithm.
Step 2: Generate  SHA-256 hash of the server seed (i.e. generated in step 1).
Step 3: Generate next server seed following RNG algorithm.
Step 4: Generate  SHA-256 hash of the next server seed (i.e. generated in step 3).
Step 5: Generate a client seed using front-end javascript of user's browser.
Step 6: Show SHA-256 of the server seed (generated in Step 2), SHA-256 of the next server seed (generated in Step 4) and client seed (generated in Step 5) to the user.

Now if user decides to change the client seed, he will have the SHA-256 of next server seed and can rely that casino is not cheating because casino is already committed to the server seed generated in Step 3 for next bet.

It's in the Spreadsheet. You have to scroll through the sheets and you will find the 'Hall of Fame' or you can follow this link to directly open HoF: https://docs.google.com/spreadsheets/d/1gsSA0_hoEbK6ezfzdW-BdIGxzc-hfiO0H-AvRyNTA0s/edit#gid=1608808530

Updates on My Concern about Provably Fair Implementation

I have been talking to FortuneJack representative about the issue since yesterday in Personal Messages. However, I feel it would be better for everyone to understand the matter more precisely if I post everything in public before FortuneJack representative makes any announcement on the issue here.

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Sequence 1: FortuneJack asked to me to provide more details about the issue so they can have better understanding on how the current system can manipulate the results.

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Sequence 2: My Reply containing everything in detail:

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Sequence 3: Update I received today from FortuneJack:

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Sequence 4: Now I am posting my reply to the update I received from FortuneJack:

Point No. 1: When I said that casino can provide server seed which will generate result in favor of the casino in 55+ times out of 100 rolls, I was just giving an example. It was not conclusive. Casino can assess the player's behavior pattern in whichever way it likes and show the server seed accordingly. I can write you a script if you want with which I can study the player's betting pattern over the bets, say 10K-50K bets he made and on the basis of the study, if I start showing rigged server seeds for the successive bets, I can easily draw outcomes in casino's favor in 80%+ cases(considering ~20% anomaly).

Point No. 2: There is a difference between `result` and `outcome`. Result refers to the result of the roll, example, 8.14 or 58.50. While Outcome refers to whether player won or lose the bet with the result. In current PF implementation on FJ, I agree that FJ cannot decide the `outcome` because bet is placed after seeds are generated. But FJ can surely manipulate the `result`. If FJ wants the result to be 8.14, it can make that possible by changing server seed after player changed client seed such that hash of the combination of both results in 8.14. This manipulation can be used with player's behavior pattern (as discussed in Point No. 1) and outcome can be made in favor of casino in 80%+ cases in long-run!!

Point No. 3: FJ said that the majority of the leading casinos are using the same Provably Fair System as FJ does for Dice game. I would say, just give me ONE example of LEADING CASINO which has exactly same implementation as of FortuneJack! Comparing to FJ, some big names in my opinion are: Stake, PrimeDice, Roobet, FreeBitcoin, etc. All of these casinos show the SHA-256 hash of next server seed before user has changed the client seed. So these casinos have no control on both `result` as well as `outcome`. Among all big names, FJ has the weakest Provably Fair Implementation and you guys have to accept that.

Point No. 4: It is good to know that you guys have agreed to update PF mechanism in next Dice Update. But it is wrong on your end to say that current PF implementation doesn't effect the Fairness! It surely does! It makes the Client Seed irrelevant. No matter what client seed user sets, result can still be whatever FJ decides. The biggest plus of Provably Fair Implementation is that user can make the input and casino have zero control on the final roll result. In this way, it is impossible for casino to turn outcome in its favor in long term even after studying player's betting pattern.

Point No. 5: About 2 months ago, Hhampuz had launched a bug bounty here: Bug Bounty on FortuneJack | Get Rewarded for Finding Bugs. As per the bounty, a user would be rewarded 1 BTC if he finds bug in the Fairness. I know that this bounty is over but I still believe that my concern is genuine and I deserve the payment if FJ decides to change the Provably Fair system.

-webtricks

It isn't a bug nor am I labelling FortuneJack as a 'scam'. It's just I beleive that Probably Fair Implementation on FJ is not upto the mark and can give undue advantage to casino to manipulate the results. I'm currently in talk with FortuneJack representatives via PM and providing them more details. They will soon make announcement here.

I'm really glad that you liked it. Within a week, a new and well-detailed article on Provably Fair will be published on BTCgosu.com in which everything will be explained in more details and in completely non-technical language.

It will be complemented with a Provably Fair Tool where user can verify the fairness of 33 casinos at single place.

I will publish the update here as well, once article and tool will be live on btcgosu. Stay tuned!