Subject: Re: [Bitcoin-development] Idea for new payment protocol PKI

From: Melvin Carvalho <[email-masked]>
Date: Fri, 9 Aug 2013 14:17:10 +0200

On 9 August 2013 14:08, Mike Hearn <[email-masked]> wrote:

> Bitcoin sought to reduce dependence on trusted third parties, where as,
>> persona is increasing the reach of trusted third parties.  The keys and
>> passwords are stored on mozilla's servers, sometimes on your email
>> providers.  Persona, is however, a progression and will hopefully improve
>> its security and decentralization as it goes along.
>>
>
> When Persona is supported by all the key players in a transaction Mozilla
> doesn't get anything, do they? You can easily run your own IDP on a
> personal server if you're the kind of person who likes to do that, then run
> Firefox so you have a native implementation and the Mozilla servers aren't
> involved. The keys never leave your computers.
>

You'd need to run your own email server and/or change email address, which
is not in the reach of the average user, and maybe not even of some
businesses.

>
> Whilst X.509 certs can indeed be issued for any arbitrary string, you
> still need a CA that will do it for you, and that's typically not so
> trivial. CAs aren't meant for widespread end user adoption, really, whereas
> Persona is.
>

You can self sign X.509 certificates quite easily (e.g. one click via
<KEYGEN>), then rely on a decentralized web of trust to remove browser
warnings.  A few people are working on this.

>
> I don't think Persona is any more or less centralised than other PKIs,
> really, just easier to use. Ultimately the string you're verifying is a
> user@host pair, so the host is centralised via DNS and to verify the
> assertions it vends, you must use SSL to connect to it, so under the hood
> the regular SSL PKI is still there.
>
>
>
It is easier to use, that's a great plus.  But convenience is often a trade
off with security.

I dont user user@host, I use my home page because it's easy to dereference
and get a public key.  Email is hard to dereference.

Yes, there is a reliance on DNS, which Tim calls the 'Achilles heel' of the
web, but it's held up quite well so far (fortunately for us).

Mozilla also have a master key to most email accounts, so if anyone got
access to that they could impersonate the vast majority of users that have
not opted in.  I would not use persona for financial stuff, but if I made a
casual app with non sensitive information it would be one of the top
choices, imho