Hi No I don't agree with the analysis. Yes, the PaymentRequest can be stored with the same security as the private keys are stored. The big difference is that the keys never leave the wallet. As soon as that PaymentRequest leaves the wallet on its way to the hotel server, it is up for grabs which makes it inappropriate for use as a proof of payment other than for resolving disputes and other one-time stuff. /Kalle 2015-03-13 22:31 GMT+01:00 Mike Hearn : > Hi Kalle, > > I think you're thinking along the right lines, but I am skeptical that > this protocol adds much. A saved payment request is meant to be unique per > transaction e.g. because the destination address is unique for that payment > (for privacy reasons). Where would you store the signed payment request? > Probably in the wallet. You could just extract the metadata that's useful > for UI rendering into a separate structure and then encrypt the original > full payment request under the wallet key. At least this is how I imagine > it would work. > > So then, if someone can steal a payment request they can probably steal > the wallet signing keys too, and thus signing a challenge with the wallet > keys doesn't add much. It means the wallet doesn't have to store the > PaymentRequest encrypted. But AFAICT that's about all it does. > > Do you agree with this analysis? >