Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: andytoshi on December 24, 2013, 05:31:01 AM

Title: The Rotating Coinjoiner
Post by: andytoshi on December 24, 2013, 05:31:01 AM
As discussed in the CoinJoin thread (, there is a (conceptually) simple and safe way to merge Bitcoin transactions, which can give participants improved privacy by befuddling blockchain analyses.

There are a few people working on cool clients which do CoinJoins automatically and invisibly, but until these are ready the current way to do it is basically:
1. Collect raw transactions from people.
2. Join these all together with whatever stitching method you have (probably some bitcoind/sx hack script).
3. Get signatures from each party, one after the other, until you have them all.
4. Submit the transaction.

The worst step is #3, this takes forever if you have several parties and creates asymmetries in who knows what about the transaction. There is no reason everyone shouldn't sign at once, it's just that bitcoind can't merge the resultant transactions.

So, I've written a tool which does this, and set it up here:

Now the steps (for every participant) are:
1. Submit your raw transaction.
2. After some time (right now 20 minutes later, it will tell you when), receive a joined transaction to sign.
3. Sign and submit this.

Please do not post TL;DR or ``I don't understand this'' or ``too complicated, nobody will use this''. The point of this joiner is to deal with the technical parts of manual coin joins, not to make coinjoining trivial and easy to do. (These are great goals, just not ones I have time to pursue.)

Anyway, I'm throwing it out here for you guys to play with. Detailed instructions are on the page.

Title: Re: The Rotating Coinjoiner
Post by: wumpus on December 24, 2013, 10:14:37 AM
Thanks for working on this!