[Bitcoin-development] Beyond IP transactions: towards a bitcoin payment protocol

[Pieter Wuille]

On Fri, Sep 23, 2011 at 07:21:58PM -0400, Luke-Jr wrote:
> On Friday, September 23, 2011 7:15:48 PM Pieter Wuille wrote:
> > What I want to do is to standardize part of that out-of-band communication
> > inside a protocol. 
> 
> Email and XMPP are suitable. Just sign the message with the "from" key.

I don't want to send a mail to you or chat with you when I'm buying something
in your webshop. Or do you mean my client does that automatically? Why not
through an HTTP connection like the one I'm already using anyway to view
the static address on your website?

> > The first observation is that if you want a freshly negotiated key each
> > time, some form of bidirectional communication is necessary anyway, and a
> > static txout template does not suffice anymore.
> 
> False. Deterministic keypairs remove the necessity of bidirectional 
> communication. A standard for a "public key root" "address" could be 
> worthwhile.

They still require you to give me your public key root, and me to give
you the ephemeral private key I generated, optionally together with what
I'm paying you for. That's bidirectional communication to me. Agreed, your
scheme requires a few steps less, but I believe mine is far more flexible
and user-friendly.

-- 
Pieter