Mirimir mirimir at
Sat Jan 17 10:22:02 PST 2015

Hash: SHA1

On 01/17/2015 03:52 AM, rysiek wrote:
> So,
> Mirmir wrote:
>> | 13. Targeted attacks against PGP key ids are possible
>> This is an advantage of Keybase. Then we're not depending on the KeyID,
>> or even on the fingerprint, but rather on an identity that's multiply
>> and independently authenticated.
> I keep hearing more and more about keybase, and I have a problem with it. It's 
> a centralised service, owned and controlled by a single entity; moreover, the 
> keys are tied to online identities controlled by corporate third parties 
> (Twitter, Facebook, et al). I don't see a Diaspora/The Federation support, for 
> instance.

As I understand it, Keybase is an API. The website/service is merely a
demonstration. The developers are aiming for mass adoption, and so
they've targeted the most popular sites. With some coding, arbitrary
sites could be used, with two requirements. First, it must be possible
for users to post persistent signed proofs. Second, it must be possible
for the API to access those signed proofs, in order to verify them.

> My problem with this is two-fold:
> 1. It might allow abuse, esp. MITM attacks. If Keybase becomes a /de facto/ 
> standard of acquiring keys, it seems trivial to me for them to replace a 
> valued target's key with something a LEA would provide.

That's the value of trackers. Those tracking such a comprised target
would see that various public signed proofs are no longer valid for the
target's key on Keybase. The adversary could alter all of the target's
public signed proofs. But even that wouldn't suffice, because trackers
have independent snapshot histories of public proofs. And furthermore,
snapshot histories are embedded in the Bitcoin blockchain.

> 2. It still promotes the closed, walled-gardens. Diaspora or GNU Social 
> support would not be that hard to implement.

Signed proofs could be placed anywhere that's accessible to the API. But
that takes coding, and developers have priorities. One can request.

Anyway, I've created a test identity: Once
I've added enough proofs, and have enough trackers, I plan to mess with
it by replacing the public key held by Keybase, altering some of the
proofs, and so on. Then we can see how that shows up for its trackers,
and for other users. I'll also explore impacts of malicious trackers.
Version: GnuPG v1.4.11 (GNU/Linux)


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