Management of `Harvest Now, Decrypt Later` ("HNDL") and `Post-Quantum Safety` ("PQS")

[Kreyren]

The strategy of Harvest Now, Decrypt Later relies on the ability to collect and store encrypted secrets for later decryption through e.g. sufficiently efficient Quantum Computer or in case of major vulnerability found in the cryptographic implementation.

As explained in age this appears to be a major problem as the use of GitHub API makes it trivial to collect over 23.2K files while getting a reasonable idea about what these keys are storing through the meaningful filename, for sops through it's implementation in e.g. sops-nix amounts to potentially 22.4K affected files:

Which collection is a problem now as we can't retroactively remove them from the threat actor's machine and it's sane to assume that they will be decrypted once they get access to a sufficient quantum computer.

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Please elaborate whether is sops vulnerable to HNDL to manage PQS, if it is then the users of sops should be made aware of the privacy and security implications e.g. Mic92, the author of sops-nix recommends rotate the keys so that they are useless in 5-10 years[2] and it's probably a good idea to not use sops for sensitive files that the user is not comfortable getting exposed in 5-10+ years and if they already done that to manage that situation for their threat model.

Relevants:

1. https://github.com/FiloSottile/age/issues/578
2. https://github.com/Mic92/sops-nix/issues/451#issuecomment-1846848509
3. https://github.com/matrix-org/matrix-spec/issues/975