[OTR-users] PGP integration?

Ian Goldberg ian at cypherpunks.ca
Thu Sep 27 21:43:57 EDT 2012

On Fri, Sep 28, 2012 at 02:19:22AM +0100, Ximin Luo wrote:
> Hi, are there any plans to integrate OTR keys with PGP? (c.f. how
> monkeysphere integrates SSH keys with PGP).
> It's good that crypto products don't also try to provide a PKI and
> reimplement the wheel, but then they should actually *use* existing
> ones to fill this gap!

This comes up on the list now and again.  ;-)

One big problem is that there's no way to bind the PGP key for
"bob at example.com" to the AIM ID "angrybob".  Many people already do sign
their OTR keys with their PGP keys, so if you (the person, not your
software) knows that bob at example.com is the same person as angrybob, you
can tell your OTR client that you've verified the keys.  But there's not
a good way to do this automatically.

> Also, how does OTR prevent MITM against "Q/A" and "Shared secret"
> auth[1], as I was under the impression that only physical face-to-face
> verification of fingerprints (or a derived process, e.g. PGP's WoT)
> can prevent such attacks.

When you use Q/A or shared secret auth, OTR relies on you picking a
(question or) secret that only your buddy knows (the answer to).  That
way, the knowledge of the secret is bound by the SMP to the fingerprint
of your buddy's public key.

Does that help?

   - Ian

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