this post was submitted on 06 Jul 2024
108 points (100.0% liked)
Free and Open Source Software
17952 readers
7 users here now
If it's free and open source and it's also software, it can be discussed here. Subcommunity of Technology.
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
If I'm not mistaken you can save keys in these chips so that they can not be extracted. You can only use the key to encrypt/decrypt/sign/verify by asking the chip to do these operations with your key.
That sounds only marginally better. Access to the phone still means you can create a backup containing the key, so TPM wouldn't help much.
Anti Commercial-AI license
No, why would a backup contain non-exportable information? One of the reasons to use TPM to begin with is that sensitive information can't leave it.
How do you restore a backup on another phone without the keys?
Anti Commercial-AI license
You would probably use a recovery key that exists exclusively elsewhere like on paper in a vault. Like bitlocker.
I have no idea if signal uses TPM or not but generally keys in TPM are non-exportable which is a very good thing and IMO the primary reason to use TPM at all.
One would hope the backup is encrypted.
It is. A password is generated that you have to write down. It must've been a compromise because they knew most people would just pick a shitty password if they didn't generate one and it would end up on a piece of paper or in some digital form anyway.
Anti Commercial-AI license