On Mon, Jun 16, 2014 at 10:29 PM, Daniel Rice wrote: > I'm trying to think through how to encourage the maximum number of instant > signature providers and avoid the VISA monopoly. Ideal case would be that > people can even be their own instant provider. > A provider does not have to be an interactive third party. One reason I suggested using X.509 is so secure hardware devices like the TREZOR could also be instant providers. The hardware would be tamperproof and assert using a secret key embedded in it that the tx came from a genuine, unflashed TREZOR. The the server can know the device won't double spend. In this way you have decentralised anti-double spending. Of course, it's an old solution. MintChip sort of worked a bit like this.