Cheaters (double spenders) and what the gambling sites are doing against them - page 2.

gyo9i

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Quote from: BoXXoB on April 30, 2016, 04:20:21 PM

As far as I am aware LuckyB.it system is pretty flawless as it is.

Currently the precautions they take (that I am aware of) are:

-0.0002 fee per KB with always a minimum fee of 0.0002 for instant bets
-Unconfirmed inputs must have 0.0002 fee per KB also
-The transaction must not have a malformed signature or a RBF-enabled one
-Transaction must not have output of less than 5460 satoshi

(credits to stingleword for the more detailed information)

Besides that they will not go into detail regarding the algorithm they have

It seems pretty safe and if something is not looking good they will delay bet until it is confirmed

BoXXoB

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As far as I am aware LuckyB.it system is pretty flawless as it is.

Currently the precautions they take (that I am aware of) are:

-0.0002 fee per KB with always a minimum fee of 0.0002 for instant bets
-Unconfirmed inputs must have 0.0002 fee per KB also
-The transaction must not have a malformed signature or a RBF-enabled one
-Transaction must not have output of less than 5460 satoshi

(credits to stingleword for the more detailed information)

Besides that they will not go into detail regarding the algorithm they have

BitcoinBlackjack

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Quote from: cjmoles on April 25, 2016, 07:02:48 PM

Well, I might add that the same type of scenario played out in the credit card taking online casinos. I've witnessed it many times. A person would credit his account with his credit card, make very risky wagers hoping for a large return, and if they'd lose, they'd just refute the charges on their card. Of course, if they won, they'd just allow the charge to go through and then withdraw their winnings.

Mandating a one confirmation standard for bitcoin before wagering is allowed is quite generous....allowing a zero confirmations standard is the same as allowing credit so that's a risk....gambling with credit is very risky for several reasons. And, it's not a good practice to permit.

Very good comparison! Thanks for the feedback

cjmoles

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Well, I might add that the same type of scenario played out in the credit card taking online casinos. I've witnessed it many times. A person would credit his account with his credit card, make very risky wagers hoping for a large return, and if they'd lose, they'd just refute the charges on their card. Of course, if they won, they'd just allow the charge to go through and then withdraw their winnings.

Mandating a one confirmation standard for bitcoin before wagering is allowed is quite generous....allowing a zero confirmations standard is the same as allowing credit so that's a risk....gambling with credit is very risky for several reasons. And, it's not a good practice to permit.

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Quote from: gyo9i on April 24, 2016, 02:38:14 PM

Quote from: DogecoinMachine on April 24, 2016, 02:23:20 PM

Yep, we switched to 1 confirmation deposit also. We had one double spent deposit with 20k satoshi fee.It's not really safe to allow instant deposits with higher fees.

What was transaction size? 0.0002 per kb?

It was fixed 0.0002 btc per 1 BTC.

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Not many people have the intelligence or know how to be able to double spend. It is a pretty disgusting thing to do though. People shouldn't try & pull those kind of dishonest tricks Sad

gyo9i

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Quote from: DogecoinMachine on April 24, 2016, 02:23:20 PM

Yep, we switched to 1 confirmation deposit also. We had one double spent deposit with 20k satoshi fee.It's not really safe to allow instant deposits with higher fees.

What was transaction size? 0.0002 per kb?

DogecoinMachine

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Yep, we switched to 1 confirmation deposit also. We had one double spent deposit with 20k satoshi fee.It's not really safe to allow instant deposits with higher fees.

BitcoinBlackjack

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It seems like we got the answers we were looking for. For now the 1 confirmation deposit policy will remain!
If any other website owners are having similar issues with 0 confirmations, I encourage you to do the same and protect yourselves from the cheaters.

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Quote from: BitcoinBlackjack on April 22, 2016, 08:12:57 PM

Quote from: gyo9i on April 22, 2016, 07:58:48 PM

Quote from: BitcoinBlackjack on April 22, 2016, 07:55:46 PM

Quote from: elite3000 on April 18, 2016, 05:47:16 PM

Quote from: DarkStar_ on April 11, 2016, 06:30:36 PM

You could do what luckyb.it does and wait for it to confirm with a low fee, or have instant play with a fee of at least 0.0002BTC. Should stop most double spenders, as it needs to be a large tx size for it to not confirm for a while with that kind of fee. Most players won't really notice a difference with paying 4 cents extra for the fee if they can play instantly, but it protects you a lot more. It also shouldn't affect the people that like small fees, since they can choose to wait for it to confirm.

When the network is under heavy stress or under stress tests even the 0.0002 BTC fee may take some time to be included in a block.

It is an improvement, but of course not the solution for everything

That's correct, we've seen confirmations take up to an hour with the recommended fees!

If there are no new blocks you can wait 1 hour even if you put 1 bitcoin fee

Which is exactly why we would rather do a 0 confirmation deposit policy. However safety must always come first I guess!

Yes it is true that safety must come first but if people wait too long just to deposit, how secure your site is they wont come to play because need need fast deposit. I think safety and confirmation of deposit need to be balance so this will attract more people

BitcoinBlackjack

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Quote from: gyo9i on April 22, 2016, 07:58:48 PM

Quote from: BitcoinBlackjack on April 22, 2016, 07:55:46 PM

Quote from: elite3000 on April 18, 2016, 05:47:16 PM

Quote from: DarkStar_ on April 11, 2016, 06:30:36 PM

You could do what luckyb.it does and wait for it to confirm with a low fee, or have instant play with a fee of at least 0.0002BTC. Should stop most double spenders, as it needs to be a large tx size for it to not confirm for a while with that kind of fee. Most players won't really notice a difference with paying 4 cents extra for the fee if they can play instantly, but it protects you a lot more. It also shouldn't affect the people that like small fees, since they can choose to wait for it to confirm.

When the network is under heavy stress or under stress tests even the 0.0002 BTC fee may take some time to be included in a block.

It is an improvement, but of course not the solution for everything

That's correct, we've seen confirmations take up to an hour with the recommended fees!

If there are no new blocks you can wait 1 hour even if you put 1 bitcoin fee

Which is exactly why we would rather do a 0 confirmation deposit policy. However safety must always come first I guess!

gyo9i

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Quote from: BitcoinBlackjack on April 22, 2016, 07:55:46 PM

Quote from: elite3000 on April 18, 2016, 05:47:16 PM

Quote from: DarkStar_ on April 11, 2016, 06:30:36 PM

You could do what luckyb.it does and wait for it to confirm with a low fee, or have instant play with a fee of at least 0.0002BTC. Should stop most double spenders, as it needs to be a large tx size for it to not confirm for a while with that kind of fee. Most players won't really notice a difference with paying 4 cents extra for the fee if they can play instantly, but it protects you a lot more. It also shouldn't affect the people that like small fees, since they can choose to wait for it to confirm.

When the network is under heavy stress or under stress tests even the 0.0002 BTC fee may take some time to be included in a block.

It is an improvement, but of course not the solution for everything

That's correct, we've seen confirmations take up to an hour with the recommended fees!

If there are no new blocks you can wait 1 hour even if you put 1 bitcoin fee

BitcoinBlackjack

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Quote from: elite3000 on April 18, 2016, 05:47:16 PM

Quote from: DarkStar_ on April 11, 2016, 06:30:36 PM

You could do what luckyb.it does and wait for it to confirm with a low fee, or have instant play with a fee of at least 0.0002BTC. Should stop most double spenders, as it needs to be a large tx size for it to not confirm for a while with that kind of fee. Most players won't really notice a difference with paying 4 cents extra for the fee if they can play instantly, but it protects you a lot more. It also shouldn't affect the people that like small fees, since they can choose to wait for it to confirm.

When the network is under heavy stress or under stress tests even the 0.0002 BTC fee may take some time to be included in a block.

It is an improvement, but of course not the solution for everything

That's correct, we've seen confirmations take up to an hour with the recommended fees!

elite3000

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Quote from: DarkStar_ on April 11, 2016, 06:30:36 PM

You could do what luckyb.it does and wait for it to confirm with a low fee, or have instant play with a fee of at least 0.0002BTC. Should stop most double spenders, as it needs to be a large tx size for it to not confirm for a while with that kind of fee. Most players won't really notice a difference with paying 4 cents extra for the fee if they can play instantly, but it protects you a lot more. It also shouldn't affect the people that like small fees, since they can choose to wait for it to confirm.

When the network is under heavy stress or under stress tests even the 0.0002 BTC fee may take some time to be included in a block.

It is an improvement, but of course not the solution for everything

BitcoinBlackjack

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Quote from: ndnh on April 15, 2016, 08:31:40 AM

1 confirmation is the standard (afaik). Allowing 0 confirmation deposits would certainly be a vulnerability if there are no checks on the tx fee amount etc. like luckyb.it does.

Will try to get in contact with them and see how they do it

BitcoinBlackjack

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Quote from: eternalgloom on April 15, 2016, 06:20:34 AM

I wonder how there are still some casino's that are able to offer instant play with 0 confirmations? This seems to be something that's fairly easy to exploit and make a huge profit with in a short time.
This combined with instant payouts would be quite detrimental for the site.

That's exactly why I wanted to have this discussion and see where the other gaming sites stand!

BitcoinBlackjack

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Quote from: bitkilo on April 15, 2016, 08:06:52 AM

I could see this happening whem I first read about a particular casino accepting 0 confirmation deposits but thought they would overcome this problem before implement if possible.

I guess the guy who is trying this would sort of be in a race withhimself and the miners.
He needs the first low fee transaction to take say 5min minimum to be accepted into a block (probably longer in most cases of small fees) and also try win or loose quick so he knows which transaction to push or double spend.

I would think that most bets these guys are making a high limit on games like roulette so they can bet the lot in one go on something like red/black win bets.

Yes you are 100% correct!

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Quote from: BitcoinBlackjack on April 14, 2016, 10:25:47 PM

Quote from: Evildrum on April 14, 2016, 09:43:41 PM

No one wants to help me understand how this works? Always hear about waiting for confirmations but never read how people are able to cancel a transaction?
Was thinking this should not be a issue but forgot about people being able to create infinite accounts.

I am not exactly sure how double spending works, but I can assure you that these cheaters have it down to an exact science!

Also I believe it's called a "Race Attack" which you can read about here:
https://en.bitcoin.it/wiki/Double-spending

Thank you for that link will take a look in a minute to see how this is done. The shady scammers seem to be able to sit around all day dreaming up ways to take advantage of bitcoin aspects and I hope one day they get a dose of their own medicine.

ndnh

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1 confirmation is the standard (afaik). Allowing 0 confirmation deposits would certainly be a vulnerability if there are no checks on the tx fee amount etc. like luckyb.it does.

bitkilo

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I could see this happening whem I first read about a particular casino accepting 0 confirmation deposits but thought they would overcome this problem before implement if possible.

I guess the guy who is trying this would sort of be in a race withhimself and the miners.
He needs the first low fee transaction to take say 5min minimum to be accepted into a block (probably longer in most cases of small fees) and also try win or loose quick so he knows which transaction to push or double spend.

I would think that most bets these guys are making a high limit on games like roulette so they can bet the lot in one go on something like red/black win bets.

Topic: Cheaters (double spenders) and what the gambling sites are doing against them - page 2. (Read 3059 times)