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Comment by inanutshellus | Hacker News Reader

Naive question:

This cryptography blog seems to, but... is WhatsApp really trusted as secure end-to-end encryption chat client?

Colloquially, for one thing it's now owned by one of the biggest personal-data collection companies in the world, which would have little interest in owning a chat client it couldn't benefit from data-wise. For another, I read an article mentioning it was "known" that WhatsApp decrypted your message, stored it, then resubmitted it encrypted to the destination. (Inconveniently, I can't seem to find the article now.) If, say, your life relied on privacy, would you trust WhatsApp, and if not, why?

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The protocol they use is open and very reliable, and it can be verified relatively easily from the outside that this is the protocol they're using.

If you enable backups in WhatsApp those backups aren't stored on Facebook's servers, but they are probably not encrypted very well, since you don't enter your own encryption key, and WhatsApp has to be able to decrypt those backups if you lose your device. So those probably aren't secure if you are directly targeted.

Also if you are directly targeted, it's not completely impossible that Facebook has a way to send you a custom "update" that simply sends all your messages to Facebook encrypted with their keys.

But in terms of mass surveillance, it seems fairly unlikely that Facebook can read WhatsApp messages, because something like that would not be hard to find for someone from the outside, especially since the protocol WhatsApp is supposed to use is completely known.

Facebook probably cares more about your meta-data (who has who in their address book) anyway than it cares about the content of your messages.

Or in other words, quoting James Mickens:

> My point is that security people need to get their priorities straight. The "threat model" section of a security paper resembles the script for a telenovela that was written by a paranoid schizophrenic: there are elaborate narratives and grand conspiracy theories, and there are heroes and villains with fantastic (yet oddly constrained) powers that necessitate a grinding battle of emotional and technical attrition. In the real world, threat models are much simpler (see Figure 1). Basically, you're either dealing with Mossad or not-Mossad. If your adversary is not-Mossad, then you'll probably be fine if you pick a good password and don't respond to emails from ChEaPestPAiNPi11s@virus-basket.biz.ru. If your adversary is the Mossad, YOU'RE GONNA DIE AND THERE'S NOTHING THAT YOU CAN DO ABOUT IT. The Mossad is not intimidated by the fact that you employ https://. If the Mossad wants your data, they're going to use a drone to replace your cellphone with a piece of uranium that's shaped like a cellphone, and when you die of tumors filled with tumors, they're going to hold a press conference and say "It wasn't us" as they wear t-shirts that say "IT WAS DEFINITELY US," and then they're going to buy all of your stuff at your estate sale so that they can directly look at the photos of your vacation instead of reading your insipid emails about them. In summary, https:// and two dollars will get you a bus ticket to nowhere. Also, SANTA CLAUS ISN'T REAL. When it rains, it pours.

Except my "threat model" also includes trying to minimize the data I send to the GAFAM (and others unscrupulous private companies that could potentially profit from my personal data...)

And yet, Snowden is out of the reach of the US govt (for now).

Snowden uses a lot more to defend himself than just https.

Snowden is in a situation where it would be a PR nightmare for the US if they were to touch him. That's not the same as being out of reach.

Snowden is in a situation where it could be nuclear war between Russia and the US if they were to touch him on Russian soil.

It is highly unlikely that Facebook can read WhatsApp messages. The reason I say that is that Zuckerberg said the couldn't, repeatedly and explicitly, to Congress. If there was any chance that they could, he would have either not said anything (the context would have allowed for that) or he would have dissembled. As he did numerous other times on other subjects.

As to benefiting from WhatsApp, I'm sure they benefited just fine. They bought it for the contact info from millions of non-Facebook customers that they could use to cross sell. Their growth in, for example, LatAm seems to imply that it worked ok.

Don't have the transcript - did he say that 'he' couldn't or that Facebook couldn't? Or that other agencies, facilitated by Facebook couldn't?

For example, he said at one point:

> No, we don’t see any of the content in WhatsApp, it’s fully encrypted

It's clear he's speaking about his company. Given Snowden, it would be monumentally stupid to make such a bare faced lie to Congress if they were reading, or facilitating the ability to read, unencrypted content.

Especially as he could have chosen not to say anything so specific. Congressman Schatz was talking about advertising. He could have just said something innocuous like: we don't have the ability to use WhatsApp content for advertising.

What he said there was they don't see, not they can't see.

What he also didn't say there was whether others routinely saw with Facebooks help.

Not saying they do, just saying he didn't strictly say they didn't.

He may of also being talking in the context of using content for advertising, not surveillance.

Finally a lot of intelligence gathering is just based on who has talked to who kind of networks in the first instance, rather than content because:

1. Content can be obfuscated, but not the connections

2. Easier to store and navigate

3. Less noise

If you can read your WhatsApp messages on your phone and you don't control the WhatsApp binary... then Facebook can backdoor WhatsApp to read the decrypted message.

Again, that would mean that he deliberately, explicitly and unnecessarily lied to Congress. That would pretty much require him to be an idiot. He is many things but that's not one of them.

I'm not suggesting that no-one can read them. I have no idea. I am saying that his testimony makes me very comfortable that Facebook is not because he has way more to lose from lying than from not in those circumstances.

Your argument here is that you trust Mark Zuckerberg's statement because Mark Zuckerberg wouldn't lie, because if Mark Zuckerberg lied, he would get into lots of trouble, and therefore to avoid getting into lots of trouble, Mark Zuckerberg obviously tells the truth.

I have trouble with this logic. Also, I'm not quite clear - what are the consequences for lying to Congress?

Well, maybe that works for you, but I'm more comfortable not trusting anything coming from Facebook...

Does not suggest, in any way, that nobody else can read all WhatsApp traffic, only that explicitly-Facebook employees can't.

It would be pre-2013 naive to imagine that, now that WhatsApp traffic is no longer end-to-end encrypted, no use is being made of the change.

> now that WhatsApp traffic is no longer end-to-end encrypted

I'm sorry, what?

Yes. Use Signal, or Mastodon, or WARP 1.1.1.1 if you trust that.

At any time any analytics package or update can just read whats stored client side and send it to Facebooks servers.

Is everyone intentionally ignoring this or actually unaware?

Things stored in plain text client side, can be read in plain text client side and resyndicated.

All this focus on the first transmission being encrypted while in flight and server side is just a bit negligent.

Its a system ripe for abuse and thats it.

> It is highly unlikely that Facebook can read WhatsApp messages. The reason I say that is that Zuckerberg said the couldn't,

Not wittingly.

Given that it was built by a highly trusted cryptography team, plus the fact that the protocol can be reverse engineered to confirm encryption and decryption on device, and that over-the-wire traffic has no plaintext, the trust in this is indeed very high.

WA has a lot to lose, and big enough target on it for a backdoor to have been found, if E2E is false.

Apparently anilgulecha is, like many, unaware that WhatsApp is no longer end-to-end encrypted. It technically trivial to tap the traffic between decrypting and re-encrypting stages, and the only plausible reason for the very expensive change was to enable such access.

Looking at WhatsApp's website [1], instead of saying "your messages are definitely end-to-end encrypted at all times" they say it's "available", as in this sentence:

> WhatsApp's end-to-end encryption is available when you and the people you message use our app.

Is that what you're referring to?

[1] https://www.whatsapp.com/security/

I just remember a report that the end-to-end quality inherited from its Signal origins had been removed. At the time, the innocent-ish explanation suggested was for access to keywords for ad targeting.

While I don't know much about how secure the messages are in WhatsApp, it's easy to imagine other ways Facebook could harvest data from users. They could track what you tap on in the screen, or how much you scroll, or what buttons you click on. They could still use that information to serve ads effectively in the future.

Like, how many people click on forwarded messages or pictures.

It stands to reason that for every WhatsApp conversation they'd have access to:

- who is communicating with whom,

- dates, times, and durations,

- method (text / voice / video),

- amount of data transferred,

- type of attachment if applicable, and

- location of each device,

along with unique device identifier, and perhaps other information.

See the Privacy International report[0] or video[1] on how much data FB glean from on other apps that merely use the Facebook SDK, each time an app that uses it it opened for a clue... how much more will they want from a service they paid billions for?

[0]: https://privacyinternational.org/report/2647/how-apps-androi...

[1]: https://media.ccc.de/v/35c3-9941-how_facebook_tracks_you_on_...

WhatsApp is great for casual users but not truly end to end because of its design imo. Silent rekeying is the default behavior. No perfect forward secrecy here either: old messages silently re-encrypted with the new key and re-transmitted. The Guardian and others reported on this some years back and of course you can witness the behavior yourself if you flip that setting in your client. If a buddy gets a new phone, it will now disclose that to you (but not wait to send old messages). Was that really my buddy's new phone or an attacker? Hopefully I can trust WhatsApp (but trusting the broker means it's no longer E2E).

Yes, like everyone says it's all about your threat model. If it really includes nation states, you should not use WhatsApp. Everyone else can use it for iMessage like functionality over-the-top.

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