Topic: 💡🚀 Open Source Automatic Double-Spending tool - Recover your stuck transaction - page 2. (Read 4811 times)

Minimal service fee lowered to 0.0001-0.004 for small transactions. Do not forget to Verify before broadcast.

Automatic network tx fee calculation value increased from +20% to +30% from bitcoinfees.21.co recommended fee because of high BTC network load and huge mempool size and this is still intensively growing.

Manual mode still available, you may uncheck it and use whatever network fee you want.

But please do not even try to doublespend it now with low fee - it will stuck again as previous unconfirmed transaction.

You may create your own service on home PC and not paying for several dedicated servers with full nodes and not paying for developing anything and create double-spending transaction by hands with your own knowledge and pay nothing.

Then you will try to send New TX using public well-known PushTX services https://en.bitcoin.it/wiki/Transaction_broadcasting or own Bitcoin Core and got mempool-conflict error and that's it.  And if it sent in a half times it will be dropped by other peers. But it is Free.  And most of the time this is useless especially if transaction quite "fresh" and recent.  Accelerations services are also free and it guarantee nothing.

This service is not for $10 or 0.001 transactions, but in case 1-5-10 BTC stuck it will be acceptable to someone to pay % for recovering coins and not wasting time.  Especially now during lighting fast BTC rate growing 5%+ per day.  Smaller amounts are also works but percent rate will be higher and this may not be acceptable for everyone.

It might be good idea to count your own coins but not others. Nobody forced to use this service. Too much?  Just ignore this. GL.

You should really make it way more obvious the outrageous service fee you charge. 0.005 BTC is $30, and that's your minimum charge? Seriously?

One more custom rebuilded Bitcoin Full Node added to the service for even faster TX distribution.
Double-spending TX distribution schema improved.
Also changed input selection algorithm for transactions with multiple same addresses.

Ok, just passing by and that's it. This is not for you.

Looks like you never did double-spending yourself and even not understand some details especially talking about rebroadcasting "your own confirmation transaction".   And even if you are able to make the same transaction with higher fee, you have very low chance to distribute it in the Network without special tricks.

I do not know what exactly those service does and I am not related to those service.
My service is not hold Private Keys and anyone with basic JavaScript knowledge may check and proof it.

Service use BTC Address (extracted from Private Key in user browser), previous TXID and New address and New fee to generate a new transaction at server side. After this it returns new Unsigned double-spending transaction back to User Browser and sign it inside user browser by JavaScript.

It is based on well-known Coinbin JS client, you may check whole https://txid.io website , this is a fork of Coinbin with some improvements and this is open source as well. 

The only one thing at server side - generating new transaction, because I do not offer this as free service for own reasons.

I remember there was an old site that essentially did the same thing, apart from i think you don't actually hold your private keys. Link is here but seems to be down at the moment.

Is your service essentially the same as that site's?

As regards to using this to commit fraud, these days not many sites even accept zero conf transactions even with high fees anymore. nobody is dumb enough to accept 0 conf transactions. So its not really an issue.

Most of full nodes in Bitcoin network i.e. Bitcoin Core configured by default and they will not accept double-spending transaction, because they do already have this Input spent in their mempool (original transaction) and they assume that these coins already spent. And this is correct.  They will accept new double-spending transaction only when previous one will be expired and removed from their mempool.

But there are a lot of nodes in the network and not each of them has original transaction, also some of nodes are restarting and there some new nodes started after original transaction was sent. So these nodes do not have original transaction in their mempool and they accept doublespending tx and will relay it to all peers and some peers will also accept it and relay.  The only way to spread double-spending transaction to the network in the fastest way - to send it repeatedly with some intervals to a lot of peers (not just to standard 8 peers) to have a chance to fill their mempool with a new transaction.

Everybody can create double-spending transaction manually without any services (sure you need advanced knowledge to do it) or even Bitcoin Core client can be used with some options, but this is just a half of the solution. Another half is to broadcast new transaction and sometimes it can be much more difficult than create it.

You are correct, smart people do it or they can calculate correct fees and got it confirmed within 1-2 blocks.  But there are a lot of people who do not care about fees at all.  And also some online services and wallets put wrong fee amount, i.e. blockchain.info . But if private key exportable - it can be used for doublespending.

There are also some other ways to accelarate stuck transaction like using CPFP when it possible or use some 'accelerators' but this not guaranteed.  Double-spending is the most complex solution but it 100% working  without doubts. The main issue what time it takes to deliver new transaction to miners.

https://www.cryptocompare.com/coins/guides/what-is-a-bitcoin-double-spend-and-how-does-it-work/

A double spend takes the same inputs that have been previously spent in an unconfirmed transaction, and creates a new transaction with them using a higher fee in order to get the new transaction included in a block and not the old one. The new transaction usually sends the coins to a different place from where they were being sent before, for instance, back to the person using the double spend.

The idea is; to broadcast new transaction repeatedly until confirmed without private key? I don't really get it.
This tool help everyone who want to send bitcoin but don't want to wait for so long until the transaction is confirmed but still has second option to cancel it as private key never sent out, right? Pretty useful I guess, just in case.

Looks like a nice tool but people at this point should really be using wallets that support RBF. Double-spending is an outdated solution by now.

To prevent any speculations what is bad and what is good.  
If you own Private Key - these are your coins. No other options.

This tool is not purposed for any fraud, but at least it will help to recover your own coins if transaction sent with very low fee and it still unconfimed for hours or days or weeks.  This is quite actual nowdays with sometimes huge mempool size and tx queue.

Tool is located here with full description and service rules:  
https://double-spending.com or https://txid.io/

No any other URLs related to this service.
If you see something like this in another place - it is fake page and scam!

- New double-spending transaction generated automatically;
- Actual network fee calculated automatically (manual mode available as well);
- Private Key will be never sent out from your computer, new transaction will be signed in your browser! (Open Source code)
- New transaction will be broadcasted to BTC network (periodically until confirmed) via our own specially configured nodes (no txn-mempool-conflict error)