[ANN] Coin Jumble - An implementation of CoinJoin

[belcher]

I've coded this application which is essentially a GUI around raw transactions plus an ascii-armor format for transactions similar to PGP ascii armor. The result is an implementation of CoinJoin that could conceivably be used today by non-programmers, albeit still vunerable to denial-of-service and other attacks.

Here is an group of screenshots demonstrating the application being used.
https://www.dropbox.com/s/spzbfx1ij1rrc02/cj-demo.png (click Download to get the fullsize image. size: 2.3MB)

Other implementations I've seen require that peers have to want to do a CoinJoin at essentially the same time. Given that bitcoin transaction volume peaks at about 1 tx / second, it is quite unlikely that there will be someone else wanting to transact exactly the same amount as you that is needed for CoinJoin to improve privacy.

A solution might be to allow people to share their transaction parts asynchronously. This application makes no assumptions about how the CoinJoin peers communicate, only that they can send each other ascii-armored transaction parts in a private way. They could post them on Tor hidden service forums, Bitmessage chans, I2P eepsites, Freenet pages or shared some other way.

Here is the code. One file of python along with vbuterin's pybitcointools and a socks5 library to allow anonymous lookups through tor or a ssh tunnel. Execute run.bat on Windows or ./run.sh on the command line for Linux.

https://github.com/chris-belcher/coinjumble

[gweedo]

Github, or we don't care and that image is so small, I know I am getting older but my eyesight isn't that bad.

[belcher]

Github, or we don't care and that image is so small, I know I am getting older but my eyesight isn't that bad.

Opened a github account.
Click Download to get the full-size image. I couldn't find an imagehost that would take a file that size without compressing / mangling.

[BitCoinDream]

Github, or we don't care and that image is so small, I know I am getting older but my eyesight isn't that bad.

Opened a github account.
Click Download to get the full-size image. I couldn't find an imagehost that would take a file that size without compressing / mangling.

Just lower the resolution a bit and upload it to imgur.com.

[belcher]

Github, or we don't care and that image is so small, I know I am getting older but my eyesight isn't that bad.

Opened a github account.
Click Download to get the full-size image. I couldn't find an imagehost that would take a file that size without compressing / mangling.

Just lower the resolution a bit and upload it to imgur.com.

It's a big image, lowering the resolution makes some of the text unreadable.

Nobody seems to be interested in this. Talking with some on IRC they raise a point that it's a bad idea for users to be exposed to private keys because they'll mess it up and lose their coins. So if I get time I'll make this into an electrum plugin.

[btcspry]

What was the point of this project, compared to something like JoinMarket?  Has JoinMarket replaced this project?

[belcher]

Well this was made several months before JoinMarket.

The main purpose of it now is to show you need more than a nice GUI to get adoption. It was probably used about 3 or 4 times in total.

Also CoinJumble turns out to be quite good for debugging raw transactions.

[noel57]

This is a great tool because of the multi signature PGP, have you done the final release and check for bug? Virus total scan? and other malware?
If this is entirely clean you should promote it at alphabay market on tor, sell it for 0.001 instead of free.