WhatsApp's Signal Protocol integration is now complete • Hacker News Board

Re: WhatsApp's Signal Protocol integration is now complete

#81

Post by mtgx » Tue, Apr 05, 2016, 5:19 PM UTC

moxie wrote: post #20

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'…

> They seem to have replaced TLS/SSL between client and server with "Noise Pipes". WhatsApp was already using a custom protocol instead of TLS. We worked with them to transition over to Noise Pipes, which has some advantages over what they were doing before. Also, we've renamed Axolotl to Signal Protocol: https://whispersystems.org/blog/signal-inside-and-out/

Moxie, what do you say to this?

https://twitter.com/JZdziarski/status/717399098563891200

Is that true? Are the messages decrypted server-side for iOS users?

Re: WhatsApp's Signal Protocol integration is now complete

#82

Post by zxexz » Tue, Apr 05, 2016, 5:22 PM UTC

humanrebar wrote: post #76

mike_hearn wrote: post #27

Earlier quoted context omitted.

Please read the articles. It already says that those are encrypted, as well as voice calls. Apparently once everyone is upgraded, nothing will be unencrypted. Their white paper also describes the protocols used in quite a lot of detail.

I was asking because I have a notification today in one of my chats saying that e2ee was enabled. I didn't see the same notification in any group chats. Outside of that notification, it's not clear to me when things are encrypted. Maybe the next step is a more obvious indicator.

Doesn't everyone in the chat have to have the new version of the app before it's all e2e?

Re: WhatsApp's Signal Protocol integration is now complete

#83

Post by revertts » Tue, Apr 05, 2016, 5:22 PM UTC

StavrosK wrote: post #48

mjs wrote: post #25

Is there any reasonable way to verify that end-to-end encryption is actually being used, and used correctly? From a user's point of view the app looks and works exactly the same as before, except for the addition of a QR code which could be doing anything.

What's more, my client says "You aren't secure because X needs to upgrade WhatsApp", but the other party is seeing "you are secure", complete with fingerprint and everything. I wonder which of the two devices is lying.

I hit the same thing - I think my client just had a stale view of what version the person I was talking to was running. I did a refresh of the Favorites list on iOS and it sorted it out.

Re: WhatsApp's Signal Protocol integration is now complete

#84

Post by jamesdwilson » Tue, Apr 05, 2016, 5:22 PM UTC

tptacek wrote: post #71

jamesdwilson wrote: post #66

Earlier quoted context omitted.

do you know even with source, backdoors can be hidden? open source is a must to even begin to work to verify any claims of security.

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.

I actually in agreement with what you are saying about viewing the shipped binary, but source is a must also. ideally it is a reproducible build to verify the source created the binary.

Re: WhatsApp's Signal Protocol integration is now complete

#85

Post by jamesdwilson » Tue, Apr 05, 2016, 5:23 PM UTC

kmch wrote: post #78

jamesdwilson wrote: post #44

Earlier quoted context omitted.

no proof without open source

You could inspect the packets yourself to see that they are encrypted.

how do i know they aren't sending the chat log in a side channel, encrypted?

Re: WhatsApp's Signal Protocol integration is now complete

#86

Post by jamesdwilson » Tue, Apr 05, 2016, 5:24 PM UTC

kmch wrote: post #78

jamesdwilson wrote: post #44

Earlier quoted context omitted.

no proof without open source

You could inspect the packets yourself to see that they are encrypted.

skype is encrypted too, and backdoored. don't forget whatsapp is owned by facebook.

Re: WhatsApp's Signal Protocol integration is now complete

#87

Post by tptacek » Tue, Apr 05, 2016, 5:25 PM UTC

pilif wrote: post #59

What the article fails to mention: 1) I would assume Facebook still gets unencrypted access to my address book for use with their shadow profiles 2) We have zero control over what key the client encrypts the messages for. Is it only the other peer's phone? Or is it for the peer's phone plus Facebook for analysis of the messages? Especially 2) is of some concern to me (against 1 I can't protect myself anyways because…

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 sensitivity:

- WhatsApp - iMessage

Tier 3 secure messengers: secure messaging protocols with flaws, limited cryptanalysis, only content-controlled browser clients, &c

- Redacted to avoid flamewars.

Everything else: insecure; use only to bootstrap conversations to a Tier 2 protocol (knowing that if you're a state-level target, you're exposed even after you "upgrade")

- Google Talk - Facebook Messenger - AIM

I think WhatsApp would like to be a tier 1 secure messenger (they'd be the first mainstream tier 1 secure messenger!) and they have a shot at being that, but they're probably some years away from it.

† (I know PGP and OTR are cryptographically limited compared to Signal Protocol, but from an OPSEC perspective they're still a tier above iMessage.)

Re: WhatsApp's Signal Protocol integration is now complete

#88

Post by _wmd » Tue, Apr 05, 2016, 5:26 PM UTC

> As of today, the integration is fully complete. Users running the most recent versions of WhatsApp on any platform now get full end to end encryption for every message they send and every WhatsApp call they make when communicating with each other

Emphasizing "running the most recent versions of WhatsApp", does this mean the fancy new protocol can still be downgraded to the old one by an older client? I'd save the fanfare for a few more months yet

Re: WhatsApp's Signal Protocol integration is now complete

#89

Post by folz » Tue, Apr 05, 2016, 5:26 PM UTC

_wmd wrote: post #88

> As of today, the integration is fully complete. Users running the most recent versions of WhatsApp on any platform now get full end to end encryption for every message they send and every WhatsApp call they make when communicating with each other Emphasizing "running the most recent versions of WhatsApp", does this mean the fancy new protocol can still be downgraded to the old one by an older client? I'd save the f…

Nope. From the article: "Once a client recognizes a contact as being fully e2e capable, it will not permit transmitting plaintext to that contact, even if that contact were to downgrade to a version of the software that is not fully e2e capable. This prevents the server or a network attacker from being able to perform a downgrade attack."

Re: WhatsApp's Signal Protocol integration is now complete

#90

Post by dest » Tue, Apr 05, 2016, 5:27 PM UTC

tptacek wrote: post #73

dest wrote: post #64

Earlier quoted context omitted.

Taking the example of Skype, the hardening/on-the-fly decryption techniques used in the binary made the reverse engineering very difficult [0]. Difficult to reliably audit such software. Don't know about Whatsapp though. [0] http://www.oklabs.net/skype-reverse-engineering-the-long-jou...

That was true in the case of Skype (which was eventually reversed), but it is not true here.

Maybe it is feasible, but at the very least I would wait for someone to reverse engineer it and publicly publish its findings. I do not have the skills to do that.

Moreover, if reverse engineering is so easy, why not open-source it from the beginning?