Sending private keys instead of transactions

[aral]

Alice receives the BTC from teh exchange on address A1.  She transfers from A1 to A2, sends the private key to Bob who can then transfer from A2 to B1 and then, to the exchange through an address B2 that is tied to him.  So there is still a link between Alice and Bob. 

Alice sends the private key to Bob using Tor or i2p or whatever. Nobody sees this. If there are intermediaries (such as in my last posting) it gets just better. Think of it as a remixing cascade for bitcoins, if you wish.

If Alice uses the bitcoin client to send money to Bob, everyone sees it in blockexplorer.

If Bob creates a fresh address and Alice sends money to it, nobody is going to know it's Bob's address until he associates himself with it.  He could create it offline and it could never have been seen by the network.  You already can't get more anonymous than that and there is no need for Alice to know the PK. Whatever you do, though it can be made obscure, the transaction will be somehow linked to Alice through the exchange records. 

[bcearl]

Welcome back, double spending!

No. The difference is just the moment in the protocol where this is prevented.

Suppose Alice double spends a coin to Bob and Carol in the traditional Bitcoin protocol. Where will this be found? When forming and stabilizing the block chain, so Bob will know some 20 - 25 minutes later. Therefore, Bob will wait 20 - 25 minutes to make sure, everything is fine.

Now have a look at the proposal. Suppose Alice keeps a copy of the private key. Alice sends the private key to Bob. In order to make sure the money is his Bob immediately uses the private key to forward the money to a fresh address where he is the only one to have access to. Suppose Alice tries to cheat by transfering the money before Bob has done so. Bob will know 20 - 25 minutes later.

So in both cases Bob will wait some 20 - 25 minutes later.

Welcome back careful reading of forum proposals. 

If you do it like that, where is the advantage? Who cares whether Alice or Bob starts the transaction?

[Forp]

If Bob creates a fresh address ...

That's the point. If.

Currently, it looks like, there are three types of transactions. People using the satoshi client, special institutions like miners, Mt Gox, exchanges and stuff - and a rest consisting of "strange" transactions directly fed into the system.

I am not interested in what could be done with the current system but what IS done with it. I have not yet reached all conclusions, but you can see quite a bit more in network analysis than I feel comfortable with. That's why I am concerned.

I hope, if I have a bit of time and in a few weeks, I can be more specific.

[brendio]

It's great when the sender doesn't care who receives it:

-key written on something and given to a winner at a party
-physically giving someone a pre-loaded account they can use
-geo caching - rather than leaving usb sticks or whatever all you do is write down the code
-scratchcards
-you could even have meet-ups where everyone gets a card where inside everyone has a code. Some are worth 0.01 some are worth 1. It would be kind of fun to use.

I think it's useful when you want to exchange value in a non-digital way.

For example. I don't care what happens to 0.05 BTC here:
1GX4zUSao2YDy2k6YdWqoHVhT4C66AGnxh (it will be there soon)
Whoever spends it first using this private key:
5Hri33arpk1BmhDaHwJw8HiwzTxi9PWtidTWBhCEBuEtHgDcVJM
Gets it.

Key's made with my BOTG script.

I really like your ideas. I was thinking about things like the geocaching idea before. The major problem at the moment is the difficulty of importing the keys back into the bitcoin client. I was mulling over some ideas in this thread and I think that putting some Bitcoin in a newly created instawallet and then giving that instawallet address to the recipient, whether as straight text url or a QR code that can be scanned into a smart phone,  may allow you to achieve some of the above applications (assuming you trust instawallet).

[aral]

"strange" transactions directly fed into the system.

...

I hope, if I have a bit of time and in a few weeks, I can be more specific.

OK, could be interesting.  But can you give an example of one of the strange transactions?

[phillipsjk]

I really like your ideas. I was thinking about things like the geocaching idea before. The major problem at the moment is the difficulty of importing the keys back into the bitcoin client. I was mulling over some ideas in this thread and I think that putting some Bitcoin in a newly created instawallet and then giving that instawallet address to the recipient, whether as straight text url or a QR code that can be scanned into a smart phone,  may allow you to achieve some of the above applications (assuming you trust instawallet).

What we need is a bitcoin client that can support multiple, possibly "tainted" wallets. "Tainted" wallets should be transferred to a new wallet as soon as possible. The bitcoin client should also let you choose which wallet you move the funds to. Any encryption should be set on a per-wallet basis.

[Forp]

OK, could be interesting.  But can you give an example of one of the strange transactions?

Those that are designated "strange" in block explorer.