Comments on: Keybase: Mostly Painless Public Encryption

By: Lou

Lou — Mon, 10 Nov 2014 00:40:58 +0000

I wouldn’t mind checking out this service – if you have any invites left I would appreciate one as well.

Thank you,
Lou

By: Hexren

Hexren — Sun, 08 Jun 2014 15:19:35 +0000

Hey,

If there are still invitations I’d like one :)

Hexren

By: Wesley

Wesley — Wed, 04 Jun 2014 01:59:32 +0000

Looking more at their website, giving out a different public key wouldn’t work. When you verify, you publish a signed message, thus if keybase.io sent a diffrent one, the client would detect that and reject the key.

So, you only need to trust the client, and it’s open source :)

By: Rahmat Budiharso

Rahmat Budiharso — Tue, 03 Jun 2014 08:43:22 +0000

By: Luke Maciak

Luke Maciak — Tue, 03 Jun 2014 04:59:35 +0000

@ Wesley:

To sign, yes. To encrypt no. You can encrypt a message without signing it. So if Bob is smart, he will sign all this messages so that Alice can tell if there is any tampering going on. The NSA (or enemy spies or whoever) could still read Bob’s initial message, and if if he was whistle-blowing or spying or whatever, he could still get v& though.

By: Wesley

Wesley — Mon, 02 Jun 2014 22:44:46 +0000

@Luke

> They grab alice.asc from Keybase, re-encrypt it this time for reals, and send it to Alice.

This is that part I’m confused on. Won’t they need Bob’s private key to sign/encrypt it?

By: Luke Maciak

Luke Maciak — Mon, 02 Jun 2014 22:39:56 +0000

@ Wesley:

I think that the scenario mentioned by @ Dr. Azrael Tod goes as follows:

– Alice signs up for Keybase and uploads her public key alice.asc
– NSA (or whoever) coerves Keybase to secretly generates a fake key fake.asc based on their private key
– When when someone goes to check Alice’s profile they see alice.asc
– When Bob logs in, and check Alice’s profile Kebyase is told to serve him fake.asc instead
– Bob encrypts a secret message to Alice using fake.asc and emails it to Alice
– NSA intercepts the email before it reaches Alice and decrypts it.
– They read the message and immediately dispatch Party Van to fetch Bob
– They grab alice.asc from Keybase, re-encrypt the message, and send it to Alice as if nothing happened
– Alice is none-the-wiser and Bob is in secret off-shore prison

The scenario of course requires the third party to be able to compromise both Keybase and the medium Bob and Alice choose to exchange information (so presumably Gmail) which is not that far fetched given Prism and all.

By: Wesley

Wesley — Mon, 02 Jun 2014 21:26:22 +0000

@Dr. Azrael Tod:

If I got a message from Bob that was plaintext after sending him an encrypted message, I would be suspicous as hell. That doesn’t stop keybase from reading my message, but it stops a total man in the middle attack.

Installation isn’t a problem from me, being on Arch Linux it’s in the AUR. That means that there’s a nice little bash script that will make a package of it with all the depends of everything taken care of :)

By: Luke Maciak

Luke Maciak — Mon, 02 Jun 2014 21:00:55 +0000

@ Wesley:

@ Dr. Azrael Tod:

Yeah, the thing could potentially be abused quite a bit. It’s interesting how increasing UX tends to decrease the actual security of a system by generating use cases where system would be easy to abuse, or by introducing a third party with implied trust. :(

But, it’s the most interesting thing I have seen being done with public encryption as of late. So as long as we are cautious and keep in mind the risks, I have no problem supporting what they are doing. :)

Oh, and NodeJS is already installed most machines I own because I use Grunt, Bower and Yeoman a lot. So I actually did not think of that as a downside. Ruby, Python and Node are usually the three things I install immediately upon booting up a new machine. :)

By: Dr. Azrael Tod

Dr. Azrael Tod — Mon, 02 Jun 2014 20:37:16 +0000

@ Wesley:
well i was speaking of encrypting it _for_ alice to decrypt with alice’s private key. For that you only need the public key. Of course, you couldn’t sign as bob.

the matter of giving users a way to upload private keys is just another thing…
ok, it “should” be encrypted and somewhat secure (if the key isn’t “1234”). But really?

The last big problem i have with keybase is that the software by them needs node.js and should be installed via npm. Things you plainly will never see on computers i controll.
that wouldn’t be a problem if they had small bash-scripts for everything (they have for some things like registration and signing auth-messages for twitter/github/whatever).
but they lack this for “tracking” (thats signing keys afaik?)

…and keybase.io is no real keyserver that i could use with existing software. But that’s just a missing feature.