WARNING : deprecated key derivation used. Using -iter or -pbkdf2 would be better.

[osopolar]

On newer openssh versions I get the following warning:

*** WARNING : deprecated key derivation used.
Using -iter or -pbkdf2 would be better.

So using -pbkdf2 -iter 1000000 might be better, but this would require to re-encrypt the current encrypted tokenfiles with the new settings. So a re-encrypt command would be nice. See also https://askubuntu.com/questions/1093591/how-should-i-change-encryption-according-to-warning-deprecated-key-derivat