I think you can use your nostr key as a pgp key.
https://hashelse.medium.com/how-to-sign-and-verify-a-document-or-file-using-pgp-gpg-401d013d2405
Discussion
I tried importing my naec to open keychain. Maybe I need to convert to hex?
Most probably it has to be hex
How do I do that? (I'm a welder not a coder)
Hmmm, wait! 🫣 Don't put your nsec there.
Was rushing because my internet went away. And mixed with the npub converter. It is for converting npubs to hexs vica versa.
To convert the nsec, I will write you tomorrow! I will also quickly try to do the signing as well to let you know if it works!
Think somebody already figured this out....
That is cool! Have you tried it? It seems a good solution for your usecase.