[VOIPSEC] About ZRTP (was Governments employing MiTM attacks against SSL)

[T Biehn]

Also it's worthwhile to mention that when using ZRTP for deciding on a key
the class of attack mentioned in the OP (government mitm on ssl) doesn't
apply, as ZRTP uses a first-exchange whitelist for parties that you contact,
instead of PKI that could be subverted.

It's still vulnerable if MITM is performed on first-connect.

-Travis

On Wed, Apr 21, 2010 at 10:35 AM, Pablo Rogina <pablojr at gmail.com> wrote:

> > I see you mentionned ZRTP on your posting. Can you (or any body else)
> compare and contrast ZRTP vs SRTP by measuring their security
> > behaviors. Thank you!
>
> As mentioned before, ZRTP is used for key agreement by the *UAC*s (user
> agent client) and once the keys are generated, they're used in a SRTP
> session.
>
> One main purpose of ZRTP is to avoid the need to establish previously a PKI
> (private key infrastructure) in order to get session keys for later use in
> SRTP. ZRTP is based on Diffie-Hellman key agreement protocol.
>
> That way, two people using softphones that support ZRTP natively (i.e.
> QuteCom) or by using other softphones with Zfone (*zfone*project.com)
> installed,
> you'll have encrypted calls without the need of digital certificates or
> both
> ends having to share keys before placing the call.
>
> Pablo J. Rogina
> _______________________________________________
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> Voipsec at voipsa.org
> http://voipsa.org/mailman/listinfo/voipsec_voipsa.org
>



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