I personally wasn't familiar with D-PKGs but his response allowed me to understand what they were pretty easily.
I'd worry about the extra attack vectors because of that - man in the middle, snooping browser extensions, etc (or even just strong-arming them into silently changing their javascript do no encryption)
To his credit, he writes about this as well:
> On a trust scale, is it better to use PGP or PrivateSky if you want to be 100% sure that no one can see your data? Answer: There is no question that [...] a system such as PGP is better [...]
> There is only one problem. PGP and the current state of the art are too damn hard for the general population at large to use. [...]
I use enigmail + thunderbird, and it's pretty simple to use. It's only difficult because the tools are immature. Sending a mail and seeing a "verified from [email protected]", or "can only be viewed by [email protected]" isn't difficult to understand.
The smartphone vendors are in a unique position where they could make this happen.
The hard part has always been key management. If a user doesn't have a properly managed web of trust, they have no real assurance of privacy or authenticity.
I think the people who are actually in a position to fix this problem are the social networks. Imagine if the act of joining Facebook caused a keypair to be generated by you, and friending someone brought their key into your web of trust with some sensible defaults.
Unfortunately Facebook has no incentive to build such a thing. But maybe something third party can leverage all those social connections to help users manage keys in a more natural way.
Can you elaborate?
So, rather than allay fears about his service, I'm left feeling more skeptical about their claims.
I would love hear from people more versed in cryptographic key exchange protocols as to the basis for their claims.
And, seriously, a Michael Scott protocol?