Keybase

[Jesse B. Crawford]

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I have a Keybase profile at
	https://keybase.io/jcrawfordor
I have several invites available as well if anyone else is interested.

I think of Keybase very positively, it is perhaps not perfect but it's
a big improvement in usability for typical people than the
web-of-trust system. Attaching cryptographic keys to social network
identities matches how most people really use the internet very well.

Perhaps this has already been mentioned, but it's worth pointing out
that the Keybase service (keybase.io) is NOT trusted to verify the
proofs. The keybase command-line tool verifies the proofs
independently itself, preventing the keybase service lying.

That said, I would not advocate uploading your private key to keybase.
There is a huge usability tradeoff surrounding this, and while Keybase
is trying to maintain as much security as possible, I'm not yet
convinced that it is safe to provide the private key to a third party
even if they have zero knowledge (primarily because of problems with
web browser cryptographic implementation).

Jesse B. Crawford
Student, Information Technology
New Mexico Inst. of Mining & Technology

https://jbcrawford.us // jesse at jbcrawford.us
https://cs.nmt.edu/~jcrawford // jcrawford at cs.nmt.edu

On 2015-01-17 15:12, Mirimir wrote:
> On 01/17/2015 01:34 PM, rysiek wrote:
>> Dnia sobota, 17 stycznia 2015 11:22:02 Mirimir pisze:
>>> 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.
> 
>> Wait, how/where does Bitcoin come into this? Did I miss it
>> somehow? I admit I didn't dive into keybase increadibly deep, but
>> still...
> 
> See <https://keybase.io/docs/server_security> and re the
> blockchain 
> <https://keybase.io/docs/server_security/merkle_root_in_bitcoin_blockchain>.
>
>  | Every public announcement you make on Keybase is now verifiably 
> | signed by Keybase and hashed into the Bitcoin blockchain. To be |
> specific, all of these: | | o announcing your Keybase username and
> your public key | o identity proofs (twitter, github, your website,
> etc.) | o public bitcoin address announcements | o public tracking
> statements | o revocations of any of these
> 
>>>> 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.
> 
>> Right.
> 
>>> Anyway, I've created a test identity: https://keybase.io/Proba.
>>> 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.
> 
>> Oh, great, I really appreciate that effort. Please keep me
>> posted!
> 
> Thanks. If you join, you can play :) I'm
> <https://keybase.io/mirimir> and the test account is
> <https://keybase.io/proba>.
> 
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