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'As such I think it's unfair to just complain about WhatsApp here.' I disagree. WhatsApp have a known vulnerability which they won't fix (indeed they deliberat

by agd 10y ago

'As such I think it's unfair to just complain about WhatsApp here.' I disagree. WhatsApp have a known vulnerability which they won't fix (indeed they deliberately added this vuln on top of the Signal protocol), and no denial that they have used this vulnerability in the past. They made a big PR song and dance about this feature only to backdoor it. That deserves criticism.

lucb1e 10y ago
Exactly -- plus, the "notify key changes" setting is off by default. When I was looking through WhatsApp on my girlfriend's phone (it's useful to know what popular applications look like to be able to help others, even if I don't use them myself) I was very surprised to learn it was off by default. That's the same as disabling certificate checking on https and hoping that the pubkey you got is valid. It took me a while to believe it was actually the default and she hadn't turned it off herself (probably by accident), but it seems to be true. I just can't imagine how people call Whatsapp encrypted when whatsapp can push a new key à la "here, go encrypt your messages to this pubkey please".
- pilif 10y ago
  > plus, the "notify key changes" setting is off by default that's the thing: That setting is pure placebo security-theater. There's nothing to guarantee that this setting actually causes notification on all key changes, whether it's on or off. Knowing that we all have trouble trusting Facebook, we can assume that all this setting does is inform users when their counterpart has a new phone (which in itself is a very slight privacy issue. I might not want you to know that I have a new phone / reinstalled WhatsApp). It won't inform users when Facebook adds another public key for analytics and it also won't inform when the NSA adds a key through their special surveillance interface Facebook built for them. That's the issue with all IM services that manage public keys for their users and thus, my original point was that it's pointless to rage against WhatsApp alone. Worse: Let's say they change the default due to the present outrage: Then everybody will be pleased with them while the actual backdoor remains in place.
  - lucb1e 10y ago
    > There's nothing to guarantee that this setting actually causes notification on all key changes, whether it's on or off. In that case the whole thing is a "placebo security theater": you cannot know whether WA implements the encryption at all. Even if you reverse engineer it and see "oh yeah there are all the necessary functions like hashing and encrypt_otr() and stuff" you still don't know whether they're actually used. Or if they're used, is there another thing that (perhaps only sometimes) sends data via another channel? But if we trust them to operate in good faith, like Whatsapp's users do, then it should be secure since the protocol they claim to use is secure. But then they break it with a default setting like this. Wtf.
pilif 10y ago
> I disagree. WhatsApp have a known vulnerability which they won't fix (indeed they deliberately added this vuln on top of the Signal protocol) how would you fix it without causing notification-blindness?
- agd 10y ago
  There's no notification blindness. If a key was changed after a message was sent, then the sender would simply be notified and they could choose to resend using the new key. This is how Signal works.
- fauigerzigerk 10y ago
  Not automatically resending messages after keys have changed might be a good start.
- Dylan16807 10y ago
  Isn't this a warning that only shows up when someone gets a new phone? That shouldn't cause many notifications.
sfifs 10y ago
The encryption protects you against others snooping on your messages in transit which is what it is meant to do. Absolutely mothing really stops any of WhatsApp, Apple or even Signal itself from reading your messages if they want to/are compelled to. The only way to protect yourself against the service provider is to manage public keys yourself manually using GPG like workflows which have proven to be unworkable. The trade off is do you want free and easy to use messaging which protects you from other snoopers but not the service provider/government itself or do you want much more secure systems that no one outside the technology priesthood will use.

by agd 10y ago

lucb1e 10y ago

Exactly -- plus, the "notify key changes" setting is off by default. When I was looking through WhatsApp on my girlfriend's phone (it's useful to know what popular applications look like to be able to help others, even if I don't use them myself) I was very surprised to learn it was off by default. That's the same as disabling certificate checking on https and hoping that the pubkey you got is valid. It took me a while to believe it was actually the default and she hadn't turned it off herself (probably by accident), but it seems to be true. I just can't imagine how people call Whatsapp encrypted when whatsapp can push a new key à la "here, go encrypt your messages to this pubkey please".

pilif 10y ago
> plus, the "notify key changes" setting is off by default that's the thing: That setting is pure placebo security-theater. There's nothing to guarantee that this setting actually causes notification on all key changes, whether it's on or off. Knowing that we all have trouble trusting Facebook, we can assume that all this setting does is inform users when their counterpart has a new phone (which in itself is a very slight privacy issue. I might not want you to know that I have a new phone / reinstalled WhatsApp). It won't inform users when Facebook adds another public key for analytics and it also won't inform when the NSA adds a key through their special surveillance interface Facebook built for them. That's the issue with all IM services that manage public keys for their users and thus, my original point was that it's pointless to rage against WhatsApp alone. Worse: Let's say they change the default due to the present outrage: Then everybody will be pleased with them while the actual backdoor remains in place.
- lucb1e 10y ago
  > There's nothing to guarantee that this setting actually causes notification on all key changes, whether it's on or off. In that case the whole thing is a "placebo security theater": you cannot know whether WA implements the encryption at all. Even if you reverse engineer it and see "oh yeah there are all the necessary functions like hashing and encrypt_otr() and stuff" you still don't know whether they're actually used. Or if they're used, is there another thing that (perhaps only sometimes) sends data via another channel? But if we trust them to operate in good faith, like Whatsapp's users do, then it should be secure since the protocol they claim to use is secure. But then they break it with a default setting like this. Wtf.

pilif 10y ago

> I disagree. WhatsApp have a known vulnerability which they won't fix (indeed they deliberately added this vuln on top of the Signal protocol) how would you fix it without causing notification-blindness?

agd 10y ago
There's no notification blindness. If a key was changed after a message was sent, then the sender would simply be notified and they could choose to resend using the new key. This is how Signal works.
fauigerzigerk 10y ago
Not automatically resending messages after keys have changed might be a good start.
Dylan16807 10y ago
Isn't this a warning that only shows up when someone gets a new phone? That shouldn't cause many notifications.

sfifs 10y ago

The encryption protects you against others snooping on your messages in transit which is what it is meant to do. Absolutely mothing really stops any of WhatsApp, Apple or even Signal itself from reading your messages if they want to/are compelled to. The only way to protect yourself against the service provider is to manage public keys yourself manually using GPG like workflows which have proven to be unworkable. The trade off is do you want free and easy to use messaging which protects you from other snoopers but not the service provider/government itself or do you want much more secure systems that no one outside the technology priesthood will use.