Okay, but can’t it be an optional feature? I’d like it if a new device could download message history from an old device by having both online at the same time.
Comment on A fresh install of Signal takes up 410MB, blowing both Firefox and Chromium out of the water
stepan@lemmy.cafe 6 months ago
The unability to continue chat from phone is a feature.
NeatNit@discuss.tchncs.de 6 months ago
randombullet@programming.dev 6 months ago
Optional how so? It’s a rotating key. Unless you have all of those keys to export into your computer, then you’ll be stuck with the current synced key.
JackbyDev@programming.dev 6 months ago
I don’t see why the current key can’t encrypt old messages and send those. I admit I might be missing something obvious though. Maybe something like not wanting to accidentally leak old messages? As in it’s less attack surface or something?
Natanael@slrpnk.net 6 months ago
You can still push old message history to your other devices, you can re-encrypt
randombullet@programming.dev 6 months ago
No shit. I’ll need to look into this. Thanks for learning me up.
Illuminostro@lemmy.world 6 months ago
[deleted]stepan@lemmy.cafe 6 months ago
Thanks
ovalofsand@lemmy.world 6 months ago
Unabilifiedness
Lucidlethargy@sh.itjust.works 6 months ago
What does this mean? I use my phone and computer, and they sync up in real-time without any issues.
stepan@lemmy.cafe 6 months ago
It means that if you have chats on one device and install Signal on another one, the chats don’t transfer to it. After you link new device, new chats do sync perfectly fine.
explodicle@sh.itjust.works 6 months ago
After they dropped SMS support and called that a feature, now I can’t wait for their hottest new bug!
bss03@infosec.pub 6 months ago
New messages will show on all your devices, but yes, it is intentional that old messages are not available to new devices.
scarilog@lemmy.world 6 months ago
This is because they don’t retain your messages on their servers right? Is this for storage reasons, or more just security philosophy of not being able to access ast chats when you login from elsewhere?
JoeyJoeJoeJr@lemmy.ml 6 months ago
This is not entirely correct. Messages are stored on their servers temporarily (last I saw, for up to 30 days), so that even if your device is offline for a while, you still get all your messages.
In theory, you could have messages waiting in your queue for device A, when you add device B, but device B will still not get the messages, even though the encrypted message is still on their servers.
This is because messages are encrypted per device, rather than per user. So if you have a friend who uses a phone and computer, and you also use a phone and computer, the client sending the message encrypts it three times, and sends each encrypted copy to the server. Each client then pulls its copy, and decrypts it. If a device does not exist when the message is encrypted and sent, it is never encrypted for that device, so that new device cannot pull the message down and decrypt it.
For more details: signal.org/docs/specifications/sesame/
Rin@lemm.ee 6 months ago
That’s for your insightful comment. I’m now going down the rabbit hole of the signal spec :)
huginn@feddit.it 6 months ago
Correct
Squizzy@lemmy.world 6 months ago
But if I reply on the phone will it populate the desktop chat and vice versa?
JoeyJoeJoeJr@lemmy.ml 6 months ago
Yes, as long as you set up the desktop client before sending the message.
Messages sent with Signal are encrypted per device, not per user, so if your desktop client doesn’t exist when the message is sent, it is never encrypted and sent for that device.
When you set up a new client, you will only see new messages.
See signal.org/docs/specifications/sesame/ for details.
Squizzy@lemmy.world 6 months ago
Cool, could I recover a backup to te desktop to have access to the historical ones?
Fetus@lemmy.world 6 months ago
The chat continues on all linked devices from the point in time that they are linked.
Imagine two people having a face-to-face conversation, then a third person walks up and joins in. The third person doesn’t know what was said before they joined the conversation, but all three continue the conversation from that point on.
Linked devices are like the above example, if two of those people were married and tell each other every conversation they’ve had since their wedding.
JoeyJoeJoeJr@lemmy.ml 6 months ago
There is no sharing of messages between linked devices - that would break forward secrecy, which prevents a successful attacker from getting historical messages. See the first bullet of: support.signal.org/…/360007320551-Linked-Devices
Messages are encrypted per device, not per user (signal.org/docs/specifications/sesame/), and forward secrecy is preserved (en.m.wikipedia.org/wiki/Forward_secrecy, for the concept in general, and signal.org/docs/specifications/doubleratchet/ for Signal’s specific approach).
eksb@programming.dev 6 months ago
There is no reason why the message sync that works from phone to phone could not be implemented on the desktop client as well.
Fedibert@feddit.de 6 months ago
Yes