I find it more likely that they want to protect and to be seen to protect their users.
So another act in "security" theater for most people. They must keep everyone guessing at what they will do next.
How is this security theater? It's providing an actual, useful service for those who choose to use it. If the majority of people choose not to, then the fault would lie primarily on the end user, not on Facebook.
The good news is:
a) This continues the momentum that the big Valley companies are creating around strong crypto
b) This will motivate people to build better replacements for PGP, because now they know that they might actually receive encrypted emails if they can get sweis and others at Facebook on board.
S/MIME would have been slightly better, IMO, but I understand why they didn't do it that way - Yahoo and Google are working on OpenPGP browser extensions, and "copy/paste your key" is easier than "upload your certificate".
We badly need a modern, fresh take on email end-to-end crypto.
Maybe facebook has some numbers on how many users distrust other major mail providers to the extent to use this, while also trusting facebook.
At least to me, that sounds ridiculous. Because along the measures of distrustfulness of who allows information to propagate to third parties (some third parties more privileged than others…), I don't particularly see any major mail provider above and beyond any other major players…
Considering that most people wont even know what GPG/PGP are, this seems like an exercise in "Don't trust others, but trust me" and the user is supposed to go like "Welp, ok!"? Haha.
Now if we could get the public more aware of it, then that'd be great. :)
In any case, this isn't security theater. There's nothing theatrical about this. This is a real security benefit that has newly been added. Lots of things can be said about PGP in general, sure, but the ability to encrypt the messages from Facebook so that only you can read them is an actual security benefit. The entire concept of "security theater" is something that looks like it increases security but does nothing. By sheer fact that encrypting communications increases security, it can't be security theater.
Except it isn't really "only you", its whoever else has access to the key or keys facebook uses to encrypt such messages and if one distrusts other mail providers that they use to such degree, but trusts facebook, I'd really start question what threat model they are contriving…
No, you are giving FB the public key, and keeping the private key. So anyone with the (public) key you give Facebook could send you messages that you can decrypt with the private key (which is why FB also lets you publish the key on your profile page), but could not read the messages sent by someone else with the same key.
Only you -- or someone else with the private key that you don't give to Facebook -- can read the messages. Of course, if someone breaks PGP so that they can use one half of the key pair to recover the other half, they could read the message just by knowing the key you share with Facebook ... but that that is intractable is the whole foundation of public key cryptography.
Also, how is it "intractable" exactly? If you keep your key safe, you keep your key safe. If you give your private key to anyone and everyone, then it's on you if someone else reads your stuff. There's nothing inherently intractable about this. Either you're good with informational security or you aren't. Facebook has absolutely nothing to do with it.
So now that part of the puzzle has been addressed by facebook without the acknowledgement of the rest, people are suppose to just set this aside?
>…And that would be covered by a Privacy Policy and potentially the Terms of Service.
So a technical implementation with its foundation on a social contract that has and can change at any time is to be trusted…
The parent mentioned:
"Of course, if someone breaks PGP so that they can use one half of the key pair to recover the other half, they could read the message just by knowing the key you share with Facebook ... but that that is intractable is the whole foundation of public key cryptography."
Which I decided to set aside since between the user and privcy policy/tos, are the ones that seem to be the weak points that are often exploited in practice that subverts "security".
To answer your question bluntly, people are supposed to just set this aside here, yes. Because all those things are not at all even remotely related to the topic at hand. If you have concerns about PGP, there's plenty of security-oriented forums you can take those problems to to have them analyzed by actual security experts who would be able to provide much more information about it than we could. If you have concerns about Facebook's policies, then I'm sure there's legal forums and other Facebook-related discussions which would more closely match those concerns. If you have concerns about Facebook itself, well, perhaps you shouldn't be on it in the first place. But regardless, this topic is not the appropriate place for any of these conversations because none of them are about the encryption of notifications from Facebook to you.
To call this one specific feature a net security positive while being willing to silence all else (out side of empty nods to such) that is related to the encryption process for the sake of giving a pat on the back it seems, doesn't inspire much confidence…
No, the "social contract" at issue deals with a different set of concerns than the "technical solution".
The "technical solution" addresses the issue of providing a mechanism to prevent the data sent from Facebook to you being exposed to third parties without you or Facebook intending that exposure.
The "social contract" addresses limits on intentional sharing by Facebook of data related to you (which overlaps with some of the information in the communications protected by the technical solution.)
The former is not the foundation for the latter, they address distinct, though related, issues.
Uh, its the plaintext of notifications sent by Facebook, to you.
If you don't trust Facebook with the plaintext of those, you probably shouldn't have a Facebook account.
This is a means of preventing interception by third-parties not intended to have access by either of the parties to the transaction. Its kind of an orthogonal concern to the degree of trust one has in the other party, though I suppose if one sufficiently distrusts the other party, the risk of accidental interception becomes negligible compared to the risk of intentional disclosure by the other party. But if the trust is that bad, why would you even voluntarily have relationship with that party?
Good question, but It's probably best for those who trust facebook, and complain about parties that have a carte blanche to subvert such security of interception (like government actors and civilian contractors but most don't complain about the contractors) like the crowds do on HN from time to time. I ask that question to myself when I see such complaints being raised…
So really, the only one at fault for someone else reading the message would be the key owner, who's responsibility it would be to store that safely. And once again, we ask, how is this "theater"? Everything points to it being a net positive security wise. If you want to debate PGP, or the usefulness of encryption, then I'm sure there's plenty of forums for that. But in terms of the actual feature that Facebook just implemented, it's a security gain as before we had nothing, and, by definition, can't be called a security theater.