[ANN] DoubleBox.io >> Leading Double-spend tool for blockchain-related projects

[DoubleBox]

Get know DoubleBox!

DoubleBox is the leading double-spend tool for blockchain-related projects. It allows you to test your application for double-spending.

What is double-spend?

Double-spend consists in spending the same coins twice. This tool emits two different transactions using the same coins. One of the transactions goes to your target's wallet, whereas the second transaction goes back to you. Once the second transaction gets confirmed, the first one is cancelled.

Why should I care?

An application vulnerable to double-spending allows anyone using this tool to buy products and services with bitcoin, for free. From digital goods to physical products.

How to use?

Start by choosing a currency. Once you click 'next', you'll be presented a QR Code and a wallet where you must send your funds to.
Once the transaction was done, click 'Verify' and it will detect your transaction. Wait until it gets 3 confirmations.
On the next step, set the target wallet (the wallet owned by the system you are testing), the payback wallet (one that must be owned by you, where you will receive the funds back) and, if needed, set custom fees.
After it, the system will emit the first transaction. Check if the target system was able to identify it, then continue the attack to receive the funds back or cancel the attack. If you cancel the attack, the fee will be bumped (otherwise the transaction would maybe never confirm).

What if I have a problem?

Once you start a session, you'll notice a new URL which contains a session ID. A new entry will be created in your browser history. This way, if something goes wrong (you go offline, your browser crashes etc.), the URL will allow you to continue from where you have left.
If you are using Tor or private browsing, then the URL will not be saved in your browser. In this case, copy the URL to a text file in your computer  (or save it in your bookmarks).
If you did not save your URL and something went wrong, it is still possible to get back your funds. Send us an email at support@doublebox.io with as more information as you can (approx. UTC date and time, amount etc.) and a wallet where we can send your funds.

Can I get confirmations before double-spending a transaction?

No. This would only be possible through a 51% attack, where you would mine more blocks faster than all the network miners, in order to create and broadcast a longer blockchain (that would get accepted by the network). This would be pretty expensive, however.

How can DoubleBox help me in protecting my website?

If you accept crypto-currencies on your website, this tool will help you to find out if you are vulnerable to double-spend attacks. Through double-spending coins, users could get digital and/or physical products for free by cancelling unconfirmed transactions.

Website: doublebox.io

[TryNinja]

1. Do you charge any fee for this?
2. Why is the minimum that high? (0.005BTC)
3. Why should we trust you with even 0.005BTC?

[DoubleBox]

Hi!

1 - Just 5% of the amount.
2 - Sorry it was just a typo, actually its 0.0005

Thank you!

[SFR10]

AFAIK, most users (nowadays) use payment gateways/processors (for accepting payments on their websites) and with the help of those, they're already protected (mostly) against such cases + for websites that don't have automated processes, they tend to wait for confirmations first (prior to releasing the product).

IMHO, you'll have difficulty in finding someone to use your services (unless I'm missing something).

[DoubleBox]

Soon we will add support to Bitcoin Cash Double-Spend!

[DarkStar_]

Can I get confirmations before double-spending a transaction?

No. This would only be possible through a 51% attack, where you would mine more blocks faster than all the network miners, in order to create and broadcast a longer blockchain (that would get accepted by the network). This would be pretty expensive, however.

It is possible, just highly unlikely. Miners in China sometimes have issues broadcasting their block past the GFW, and what could happen is that a Chinese miner found a block around the same time a non Chinese miner found a block. What would likely happen is that the Chinese block would have good propagation in China, but poor propagation elsewhere, and vice versa. If your node is in the US, it would likely accept the non Chinese block. We can't have two blocks with the same number though, so one of them gets orphaned. If the next block is found by someone who received the Chinese block first, the non-Chinese block is orpahaned, and your 1 confirmation might go to zero.