I feel a keyfile and a passphrase provide different benefits. They can not be obtained in the same way (one you need to physically acquire, the other one you need to know). Thus, I think there is great benefit in encrypting my data using BOTH of these. That way, if one gets compromised the encryption is still intact.
Using dm-crypt in plain mode, I want to use BOTH. By default, dm-crypt uses a passphrase, and I can change that to a keyfile easily. But they seem to be the same kind of input (as in, the keyfile becomes your passphrase if provided). Using both --key-file and --verify-passphrase therefore doesn't work.
Any workarounds here to use both?