[messaging] CT (was: Thoughts on keyservers)

elijah elijah at riseup.net
Tue Aug 19 11:00:00 PDT 2014

I agree CT is off topic, but on topic to the degree to which it keeps
being suggested for user keys...

On 08/19/2014 05:45 AM, Ximin Luo wrote:

> I think people keep making the same mistake of treating CT as 
> "providing key validity". It does *not* provide key validity, nor 
> binding; it provides transparency *to enable systems that do provide
>  the former*. In other words, via the auditing and monitoring 
> components, then you gain "some confidence probability" that the key
>  is valid.


>> (1) The web server problem: a present server needs to prove itself
>>  to a present visitor. Addressed by CT, etc.

> CT does not address (1) any more than it addresses (2) or (3). It is
>  the auditing and monitoring surrounding CT that provides (1), and 
> even currently there are known gaps and it is only half-implemented 
> (no gossip protocol). As you say, "ultimately only the recipient 
> knows for sure which public keys are correct for the recipient". This
> is true *for webservers as well*.

You are making a distinction between the cryptographic log operations CT
and the monitor and auditor operations. I have not heard anyone describe
the monitors and auditors as "not CT". Is this semantic distinction

> Overall however, this is not a cryptographic problem, but a 
> logistical one. (This is why I choose the term "key validity", to 
> distinguish it from cryptographic "authenticity" once you have 
> actually validated the key.)

I thought the point of CT was that it is a logistical approach that
includes cryptography, but it does not provide cryptographic
authentication. By your distinction here, CT does provide "key
validity" but not "key authenticity", yes?


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