alt Hacker NewsPutting on my user hat...
"OK. Signal has forward secrecy. So messages are gone after I receive them. Great!"
Oh, you didn't turn on disappearing messages? Oh, right, then forensic tools like Cellebrite can get them. You have to turn on disappearing messages. The default is off.
Oh, you did turn on disappearing messages? We send the messages in notifications. So the OS can keep them. Turns out Apple was doing that. There is an option you can turn on to prevent that. It is off by default.
"I'll just delete the entire app!" No, sorry, the OS still has your messages...
At what point does the usability get so bad that we can blame the messaging system?
This same app had a usability issue that turned into a security issue just last year:
End to End Encrypted Messaging in the News: An Editorial Usability Case Study (my article)
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People keep pushing signal because it is supposedly secure. But it runs on platforms that are so complex with so much eco system garbage that there is no way know even within a low percentage of confidence if you've done everything required to ensure you are communicating just with the person you think you are. There could be listeners at just about every layer and that is still without looking at the meta-data angle which is just as important (who communicated with who and when, and possibly from where).
The median user isn't going to change default settings, so your app is as secure as whatever the default it.
> Oh, you did turn on disappearing messages? We send the messages in notifications. So the OS can keep them.
Worse than that, they did not take advantage of the ability to send that message data as an encrypted payload inside the notification.
https://blog.davidlibeau.fr/push-notifications-are-a-privacy...
Either do not include sensitive user data inside a notification by default, or encrypt that data before you send it to the notification server.
0) send a public key. 1) encrypt the file with your private key 2) send file.
WTF. This is super simple stuff.
Use SimpleX if you really want a secure messenger. Endorsed by Whonix, which in endorsed by Snowden.
I think one of the main issues is that end-to-end message encryption is a sham as long as backups are not encrypted. I could have good device security, but if the person I'm talking to does not use ADP, iMessage and WhatsApp messages get backed up with only at-rest encryption (I think Signal opts out of standard iOS backups) and possibly the same for backups of the iPhone notification database (which the article suggests as a possibility).
Similarly on Android, WhatsApp suggests unencrypted backups to Google Drive by default.
Putting on my tinfoil hat, I am pretty sure that Google/Apple/Meta have some deal (successor to PRISM) where end-to-end encrypted messaging is tolerated as long as they have defaults that make it possible to access chats anyway. Apple not enabling ADP by default and WhatsApp doing Google Drive backups that are not end-to-end encrypted is the implementation. Since most people just use the defaults, it undermines security of people who care.
It's a 'win-win', the tech companies can wash their hands in innocence, the agencies get access to data, and phone users believe that they are chatting in a secure/private manner.