WhatsApp's Signal Protocol integration is now complete

Post by tptacek » Wed, Apr 06, 2016, 12:16 AM UTC

kasey_junk wrote: post #228

codys wrote: post #221

Earlier quoted context omitted.

> If you don't have the skills to do basic verification of a non-obfuscated binary, you don't have the skills to verify an encrypted messaging protocol implementation from source either: the latter task is harder than the former! Those aren't quite the same skill though. Some folks could have the skills to verify protocols from source, but not the skills to work with a non-obfuscated binary. Task 'A' being harder tha…

I think the argument (one I'm not expert to make) is that the source may or may not be helpful to someone who is competent enough to validate a encrypted message application, but it is not what you need to verify. You must verify the binary because you cannot trust the source, so it is a basic skill of anyone who has the competency to validate an encrypted message application. Now, its possible, that the source along…

Post by cmdrfred » Wed, Apr 06, 2016, 12:26 AM UTC

Xeoncross wrote: post #206

mike_hearn wrote: post #14

This is really excellent. A few thoughts: 1) They seem to have replaced TLS/SSL between client and server with "Noise Pipes". Based on a couple of minutes Googling this seems to be a brand new one-man protocol from Trevor Perrin (the same guy who did Axoltl on which Signal is based). At least, I'd never heard of it. I wonder if this is the first inkling of a post-TLS future? http://noiseprotocol.org/noise.html 2) It'…

Could someone explain the benefit of the noise protocol? Some of us are not well-versed in the problems or attack vectors of modern crypto.

Post by tptacek » Wed, Apr 06, 2016, 12:38 AM UTC

danjoc wrote: post #270

tptacek wrote: post #71

Earlier quoted context omitted.

Your comment here is incoherent. I agree: source can easily lie. How does that make it the gold standard for verification? The reverse-engineering of the actual shipped binary (for instance, the ARM code lifted to LLVM) seems like a safer analysis target. But, what do I know.

>The reverse-engineering of the actual shipped binary (for instance, the ARM code lifted to LLVM) seems like a safer analysis target. Reverse engineering binaries is only permitted under the DMCA for the purpose of interoperability, AFAIK.[1] If so, that would make reverse engineering to verify stated security claims illegal in the United States. I'll just assume I'm wrong here for the sake of argument though. Revers…

Post by kobayashi » Wed, Apr 06, 2016, 1:24 AM UTC

dvdplm wrote: post #268

kobayashi wrote: post #263

Earlier quoted context omitted.

Why on Earth would someone from a liberal democracy want to partner with a security firm based in Iran?

To keep said liberal democracy honest?

Post by knocknock » Wed, Apr 06, 2016, 1:43 AM UTC

swombat wrote: post #108

tptacek wrote: post #87

Earlier quoted context omitted.

I think this is a reasonable analysis. I would refine it this way (examples are only for illustrative purposes): Tier 1 secure messengers: all possible tradeoffs in favor of security made; use for worst-case adversaries: - Signal/TextSecure - Pond - PGP† - OTR Tier 2 secure messengers: serious secure messaging protocols that make some tradeoffs in favor of adoption and usability; use for normal messages of low sensit…

> - Redacted to avoid flamewars. Aww... shucks.