Lest We Remember: Cold Boot Attacks on Encryption Keys

Indeed, the encryption keys can be recovered from memory fairly easily. [link] is very readable; [this video] is a well-made 5-minute introduction by the authors.

2. "with the cryogenic RAM freezing technique, presumably" - errr, no. With the "sit down at the computer and turn off the encryption/copy the data to an external drive technique", I think you'll find. Obvious bullsh*t to anyone technical but sounds 'cool' to your average 14yr old who reads these sort of sites. Errr, actually yes. You may be interested in [1] and [2]. [1] [link] [2] [this video]

You're right, I think an attack could be possible on some computers if the agents act very quickly. I don't think 30 minutes would be possible though, judging from what is said and shown in the original cold boot video: [this video]

For getting encryption keys from RAM after shutdown there's this video mentioned by another commentor: [this video] For using reflections, there's this paper implementing reading screen content from various things like reading glasses, a can of coke or even the user's eye (including a discussion of limitations): [link] Right now I can't find something on reading keyboard vibrations with lasers, but here's one doing it acoustically and one doing it via acclerometer of a phone on the table: [link] [link]