How can "undo" bitcoin transactions be "private"?

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BitUndo private transactions:

If you choose to make your undo transaction private, nobody will be able to see that you tried to undo a transaction, unless it succeed. You have to know that a private undo transaction has less chances to succeed, as is not distributed in the whole bitcoin network.

From what I know, for a undo transaction to even stand a chance of competing with the main transaction, it has to be broadcasted to the public network.

If so, then how does Bitundo "private transactions" work?

Pacerier

Posted 2014-05-24T22:53:23.770

Reputation: 2 055

Answers

2

The failed transaction won't get stored in a block on the blockchain, so it will be hard for an average person to find them. I think most of the Bitcoin nodes will delete them from memory eventually.

Also, these sneaky undo transactions are probably not broadcast so publicly in the same way that normal transactions are; they are probably sent to a smaller network of miners who want to participate in this undo system.

David Grayson

Posted 2014-05-24T22:53:23.770

Reputation: 561

But isn't it rather counter-intuitive? I mean for it to be undoed successfully it needs to be broadcasted to the public network right? Or is it such that this small pools of private networks actually have a non-insignificant chance of getting their transactions to win?Pacerier 2014-05-25T00:17:17.443

1Even if that's the case, it would be inaccurate to say that "nobody will be able to see it". The miners in question would see it.Nate Eldredge 2014-05-25T02:56:40.173

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Nate, actually, the BitUndo system doesn't have to distribute the actual undo transactions to the miners immediately, it can just distribute hashes of transactions. Then when the miner succeeds in finding the block, they would have to query Bitundo and prove they have a block and ask Bitundo to fill in all the undo transactions in that block. From my reading of http://www.bitundo.com/developer.html , it appears they are not doing it this way, but I think they could.

David Grayson 2014-05-25T06:57:51.347

Actually, only the public ones are available on the websocket server; I don't know how the private ones actually work but maybe it's something like I suggested in the last comment.David Grayson 2014-05-25T07:04:06.367

@DavidGrayson, But that seems theoretical... I mean practically speaking most miners don't do that right?Pacerier 2014-05-25T07:16:48.103