I don't get it. Obviously, the laptop is locked when it resumes, how is that key "for the taking by anyone"? I'm not saying it is impossible to read out RAM from a locked laptop, but surely not by "anyone".
There is a common misconception about how lock-screens in general work - they usually just prevents using the current hardware and software as it is to access the current OS. But the disk encryption is the main thing that prevents modification and other kind of access to actual data. And if the disk encryption key is lying in the memory, then effectively, the disk encryption is bypassed if someone can access the machine physically and assuming that there are no sufficient tampering protections in place for that machine.
Sorry, I'm probably dense, I still don't get it. You steal a laptop, you open it, the screen is locked with a password/fingerprint whatever. How do you read out the RAM from that laptop?
the term to look up is "cold boot attack" (https://en.wikipedia.org/wiki/Cold_boot_attack).
tons of cool live demonstrations of how it works on youtube if you've got the 20-40 minutes to spare
https://www.usenix.org/legacy/event/sec08/tech/full_papers/h...
Other options: DMA attacks. Also you never know what the Intel Management Engine hidden in your computer is doing. It's running a version of Minix you don't have any control over, and it has full access to memory.
Thanks, that's what I thought.
PS: Downvoting is not a rebuttal. Disk encryption is not effective security on a suspended (sleeping) system. That is a fact.
People in those high risk categories already need more than disk encryption anyway, so this isn’t even the critical piece for them! (Consider how likely it is that I would have the resources and access to freeze and extract your RAM but not, say, the ability to record you entering your password using the same access. Yes, you can come up with scenarios where that makes a difference but it really underscores that you have many additional things to worry about if this is your threat model.)
It's why I used the word "technically", by which I meant "in the absolute". What word do you propose instead? Encryption that can be worked around by anyone with skills and commonly available equipment is technically useless. It offers some protection (the thief will probably reboot or unplug) but ultimately it's null and void.
>Most people expect
This would need to be sourced. I say most people expect "encryption" to be as secure as the encryption password. In the case of an unattended sleeping computer using Linux with FDE enabled and the screen locked, it's not. I'm not sure most people know that. I believe things are different on, say, iOS. All of this was the rationale for Debian's (buggy) feature.