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Comment by spansoa | Hacker News Reader

> The memory deallocation could be improved to not to contain secrets

Attacks against RAM are as old as time. The beauty of RAM is everything gets wiped when you power off, so secrets don't persist.

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RAM does not get wiped when you power off[1] and cold boot attacks[2] are possible.

[1] https://github.com/arekbulski/Cameleonica/blob/master/docume...

[2] https://www.usenix.org/legacy/event/sec08/tech/full_papers/h...

No, unfortunately. When they swap out, they end up on disk. Sector remapping can then keep them there, even if swap space is reused.

I think there is an API in windows to mark a small part of memory as unswappable, but it can't be very big.

Even if you don't encrypt your Linux' filesystem partitions, you definately should encrypt the swap / the partition the swapfile is on. A new encryption key for the swap can be created at every boot, removing the need of an encryption password. This behaviour does make hibernation impossible, so swap encryption isn't the default on Linux distros that have opt-in encryption.

https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption

Does someone know how it's handled on Windows and macOS?

Modern AMD CPUs support memory encryption.

Unfortunately, it isn't enabled by default but needs kernel parameters.

I understand firmware vendors are to blame, and in many machines the system will freeze when you attempt to actually use this feature. This is unfortunate.

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