Yes rollorspin you are correct! Thank you for posting.

warningsigns,

The double spending problem would not be a problem at all if everyone followed the advice of the creators of bitcoin and did not trust unconfirmed transactions. However, some web sites have ignored this rule in an attempt to increase their profits by not making users wait for transactions to confirm before providing them with a service (such as betting, crytocurrency exchange, etc.).

The Glass Hunt double spend site (https://www.glasshunt.co/exploits/bitcoin-double-spend/) has been around for more than a year. All we have done with bitdoubler.io is to make a similar site that is open source, cheaper to use, and that has a lower minimum (so that users can risk less when trying out our site).

Peter Todd (one of the bitcoin core developers) has been advocating for an end to trusting unconfirmed transactions. He announced the success of his own double spend attack (https://www.coingecko.com/buzz/peter-todd-explains-how-he-double-spent-coinbase) and even published its python source code (https://github.com/petertodd/replace-by-fee-tools/blob/master/doublespend.py).

We are simply offering a service that works at the expense of others who unwisely trust unconfirmed transactions.

rollorspin,

Some sites limit the amount they will accept as an instant deposit (0 confirmations) in order to reduce losses from double spending.

crairezx20,

We would be happy to send 0.003 btc to you to test our site...you can double spend between two of your own wallet addresses and keep the btc when done testing.

Luan,

We don't have any kind of disclaimer like "this is for educational purposes only". We plainly state that our site is a tool for creating double spends and give suggestions regarding how double spends might be used to one's advantage. Apparently you did not look at our site very closely before giving your opinion.

Fire Rabbit,

When you say "I have heard a lot about bitcoin doubling sites that they are all scams" you might be thinking of "investment" sites that promise to double your money after a certain amount of time if you deposit it into the site's wallet. Our site is not a phony "investment" site, but rather a site that allows users to create double spends. It is up to the users themselves to find a way to benefit from double spends.

We can't guarantee double spends will work against any given casino. Edymola, who posted earlier, seems to have found a casino that is vulnerable. But he/she didn't specify which one. Another user posted earlier in this thread about notifying a certain casino of its vulnerability to double spends, and that casino has likely tightened up its policies on unconfirmed deposits.

If you want to test the functionality of the site you can always create a double spend where both transactions pay to different addresses in your own wallet. As far as finding a way to profit from double spends we offer some suggestions on our site, but can't offer guarantees of success against any particular site.

Edymola,

Thanks for your feedback. I'm glad to hear you had some success using our site!

throwawaytest8721,

Yesterday, a certain btc casino changed its instant deposit policies. Could this be because of your report? If you don't want to post the name of the casino in this thread could you send it to me privately?

Mpamaegbu,

My understanding is that a phishing site attempts to fool users into thinking they are on a different site, while in fact they are on an illegitimate copy of that site. If you go to our site https://www.bitdoubler.io/ and then go to the other site https://bitdouble.io/ you will see the two sites have nothing to do with each other. https://bitdouble.io/ advertises itself as a "Social Gambling Game" while our site advertises itself as a tool for allowing users to execute bitcoin double spends.

throwawaytest8721, the point is that if you bet, lose, and then double-spend your coins back to yourself then you have made a "free bet" and have the opportunity to bet again later, and maybe win next time.

rollorspin,

I don't use Shapeshift so I am not sure at what stage in the process you would want to initiate the second transaction. I think ShapeShift would be tough to fool, though, because they got hit by a double spend attack 2 years ago and are probably much smarter about protecting themselves now.

https://blog.blockcypher.com/yes-someone-double-spent-bitcoin-no-zero-confirmation-payments-are-not-dead-944d021b865e?gi=86c0d40f09ec

TheCoinFinder and olubams,

I think you are misunderstanding what the site is. It is not an investment / gambling site that promises to "double your money" after a certain time. It is a web site that allows you to create bitcoin double spends. You can read up on that here:

https://bitcoin.stackexchange.com/questions/4974/what-is-a-double-spend

Quontoloue,

Our web site is not the same domain. Our domain is https://www.bitdoubler.io/ (notice the r on the end).

player514,

You are correct. There are selective scams and exit scams. Sometimes a web site will work perfectly fine if you send it 0.01 btc. Then you might feel confident and send it 1 btc and it will keep your money. Or sometimes a web site will work perfectly for months or years and then suddenly close down and take everyone's bitcoins with it. Many bitcoin mixers, gambling sites, and darknet markets have pulled these scams. Always best to be cautious with your coins.

player514,

You are wise to be cautious about sending your btc into any new web site. The owners of the site could very well keep the money and not provide you the service they promised.

The minimum transaction amount of bitdoubler.io is only 0.001 btc. Add in the 0.0002 btc bitdoubler fee and a transaction fee of around 0.0009 btc and you could risk as little as 0.002 btc (less than $10) to test the site.

In fact, if anyone wants a free 0.003 btc to test the site with, just let us know. You can use your own bitcoin wallet addresses as the two double spend addresses and keep the money you tested with.

dumbtool45,

Thanks for your feedback. In response:

1. You said "First, just install a wordpress theme into your website, or as the ads are on youtube, you can use WIX.com". Why do you suggest adding a wordpress theme to the site? In order to improve its visual appeal?

2. You said "Second, it is not ok to have a btcdoubler after segwit? Am  I right? As far as  I know at a moment they were fighting to combat the possibility of double spend. I don't if they succeed or not." I'm not sure of the answer to that. Maybe someone else can answer that.

3. You said "They are definetely a scam. I just read all their info on their website, basically they are teaching users how to scam using double spend. People should report them and mark their account as scam I think" I would disagree that we are a scam. The web site is a tool that people might use to scam people, but the web site itself is not a scam. Meaning that the web site will work as advertised. If you create a double spend on the web site it will in fact execute the double spend (rather than just keeping your money, as a real scam web site would).

AdolfinWolf, thanks for your feedback. In response to your post:

1. We created the https://www.bitdoubler.io site to allow people an easy and cheap way to create double spends. We weren't happy with the existing double spend sites out there, such as the most popular one: https://www.glasshunt.co/exploits/bitcoin-double-spend, for a number of reasons. The Glass Hunt site charges a high fee (10% of your double spend amount) and has a high minimum (0.015 btc) amount to send. So we created a cheaper, open-source version that only charges a flat fee of 0.0002 btc and has a low 0.001 btc minimum.

2. We understand what you're saying about the immorality of double spending. Some may consider this site immoral because it can be used to fool people. We will leave it up to each individual person to decide if he or she wants to participate in double spending.

3. Not sure what you mean by "i could send transactions to myself on your site for some reason? is this a bug?." If you mean that you can put the same bitcoin address for both the first transaction and second transaction then you are correct. This is not a bug, but rather an option. If you were to send both the first and second transactions of a double spend to the same address then it would appear that the destination address would be receiving double the amount of bitcoins. This is an option we make available to users.

4. You are correct that most casinos have added double spend protections to their web sites recently. As explained in the FAQ, profiting through double spending would probably only work against new gambling sites that have not anticipated or prepared for double spend situations.

We are announcing BitDoubler: https://www.bitdoubler.io/

BitDoubler is an open source web site for double spending bitcoins. There are a bunch of similar sites out there already. But ours is different in that, first of all, it's open source, and second we charge a fee of only 0.0002 btc (about 80 cents) per double spend. Some of the other sites charge as much as 10% of your total transaction amount!

Lots of information is on the web site FAQ, so we won't unnecessarily repeat it here.

Please let us know if you have any feedback.