Multi signature scrow system. Help Please!

[Barrack Obama]

Hello guys,

I am in the works of creating a bitcoin auction site.

I'm having a lot of trouble understanding how to make a multi signature escrow system.

Heres what Im looking for:

When a user wants to purchase item he has to pay 1% commision fee then he sends his bitcoins to a escrow address. I want there to be 3 possible signatures, with two being enough to send the payment through to the vendor.

The buyer gets 1 signature, the vendor gets 1 signature, and we get 1 signature.

Are there wallets that support this?

Does a system like this already exist?

Would anyone be interested in building one, or explaining to me how to do it for some Bitcoins?

Appreciate it!

[aminorex]

http://www.bitrated.com

[fbueller]

Only bitcoind/qt. Electrum supports paying to them, but does not support signing. Best thing you can do is train your customers to use https://coinb.in/multisig - which handles keypair generation and signing. It's a very nice tool. I've tested it out, it's useful as once you pay to the multisig address, you can do all the rest in your browser without messing with the bitcoin client any more, since all you need to do is sign, which is stateless and doesn't depend on the blockchain.

If you want to try implement a multisig system, I've written a basic one in PHP. https://github.com/Bit-Wasp/multisig