Mike,

Please add Coinpunk to the list of clients that intend to support this. Thanks!

I need time to fully digest the implications of this, it's very interesting (and thank you for using protocol buffers here), but I'm initially a little skeptical as to whether this is a good approach. I think depending on central-server hot wallets has been demonstrated to be a dangerous approach to implementation of Bitcoin systems, as evidenced by the theft of millions of USD worth of Bitcoin over the last few years. I do feel like this system could potentially be just as dangerous as addresses, if not more so.

For example, as a merchant I could create a receive address on an offline computer, which is a design where your Bitcoins are very unlikely to be stolen. The trade-off is "privacy" of course, but from my chair, I'm way more concerned with security than I am with privacy. And the way I'm seeing most Bitcoins stolen right now are from server break-ins.

I also have concerns about increasing the complexity of Bitcoin transactions. This definitely increases the education curve, which is probably one of the main reasons why addresses became more popular: they are simple to understand.

It also introduces a non-Bitcoin system as a dependency, which may have far reaching consequences. What if that SSL certificate is revoked, or the government raids and confiscates the domain? If you need the domain to receive a transaction, that is quite a dependency introduced.

Again, very interesting, and I do like the CA approach, but I do have concerns about whether it is an improvement on the address system. It's my hope that there won't be a de-prioritization of the latter for the former.

My apologies in advance if I have not understood something, I have only had a chance to briefly skim over this so far and it's very possible I've misunderstood some of the machinations here and am talking nonsense.