elvisloops

8 ms·

1.
by elvisloops 1y ago
Historically as long as everything remained "in the app," it was secure. It's an easy assumption to make and communicate to others. Now it's more complicated: there are things that people can unwittingly do "in the
2.
by elvisloops 1y ago
The history of Signal has been to provide the security properties we're talking about without users having to think about it or understand. To suddenly remove forward secrecy is a very big change, and it isn't one that they seem t
3.
by elvisloops 1y ago
Yes, if Signal has effectively removed ratcheting and forward secrecy from the logical "encryption protocol" by encrypting all messages (even disappearing messages) with a single static key that never changes for your lifetime and
4.
by elvisloops 1y ago
It's not optional because you don't know whether the people you are communicating with have it enabled. One person in a group chat with the feature enabled undoes the forward secrecy for everyone in the group chat. A cloud backup
5.
by elvisloops 1y ago
If the app takes your disappearing message, encrypts it with a static key that never changes and is never deleted, and uploads it to the cloud, then the message is never truly "disappearing." A "post compromise" event wi
6.
by elvisloops 1y ago
There's a difference between what Signal does in the app and a manual action a user performs outside of the app. It is not realistic to expect that people will see a feature Signal has built for them in the app and understand the under
7.
by elvisloops 1y ago
Yes, but you don't need a complicated ratcheting protocol if you've eliminated forward secrecy in other ways. This post is about "post compromise security," but there is already no post-compromise security after the clou
8.
by elvisloops 1y ago
I think this used to be true. Now one problem is that a Signal message goes through this whole forward secrecy protocol, but the receiving device has some probability of uploading it to the cloud with a static key that never changes. You do
9.
by elvisloops 1y ago
Strange that they are posting about the "signal ratchet" when they just removed it by launching cloud backups that use a static key? Since those cloud backups include disappearing messages, that feature completely undoes all of th
10.
by elvisloops 1y ago
Giving people a 64-character key also feels uncharacteristically crude for Signal. It's not realistic to hand people 64 characters and tell them to “store this securely.” Most people will screenshot it, and those screenshots will end u
11.
by elvisloops 1y ago
It's not opt in: signal protocol for a group chat is eliminated if one person in the group chat turns this on, whether or not you do. Communicating with someone who acts adversarially is different from Signal itself adding features tha
12.
by elvisloops 1y ago
Yes, it undoes all of the security features of Signal's encryption protocol.
13.
by elvisloops 1y ago
That's not how forward secrecy works. Ciphertext isn't "deleted" unless the key used to encrypt it is also deleted. That's the point of Signal's cutting edge protocol. This undoes all of that.
14.
by elvisloops 1y ago
The implementation feels uncharacteristically crude for Signal. Instead of seamless protections, you just get handed 64 characters you’re told to “store securely.” That’s not realistic: most people will screenshot it, and those screenshots
15.
by elvisloops 1y ago
This post says disappearing messages are included in the backups. You have to enable disappearing messages with a timer of less than 24 hours to ensure that you can opt out.
16.
by elvisloops 1y ago
There's a difference between someone in your chats acting adversarially and Signal supporting/encouraging adversarial behavior as part of the way the app works. If Signal published a change to the protocol that removed forward sec
17.
by elvisloops 1y ago
I think the difference is that this is all happening in the app as a supported flow. If simply enabling a toggle in Signal (likely without understanding the implications) is now considered "adversarial," then I think that's a
18.
by elvisloops 1y ago
There's a big difference to me between storing it on device and someone else's servers.
19.
by elvisloops 1y ago
I can't believe Signal is doing this. Signal is known for its cutting-edge cryptographic protocol, but this feature has the effect of throwing that out the window and replacing it with a single static key. If a device with this enabled
20.
by elvisloops 13y ago
They are owned by Twitter. It's basically a spyware approach - Twitter wants to be able to track users across apps, but there are no cookies or tracking pixels in the mobile app ecosystem. Instead, they get developers to bundle this S
21.
by elvisloops 13y ago
I wonder why they decided to send codes over SMS that we have to manually type into a browser instead of a one-tap push notification to the Twitter app on the phone? Or Google Authenticator?
22.
by elvisloops 13y ago
Yeah! I didn't even realize there were other grocery stores other than Berkeley Bowl in Berkeley.