There is no n8n SDK for Java, so I’m afraid this wouldn’t be possible using only n8n. You can however use a Java application as described in this post here:
You could use @BramKn’s community PGP node to take care of files, though: n8n-nodes-pgp - npm
I see you linked another copy of the pgp node here @EmeraldHerald
AES node is not from me and github seems to be private, so use at your own risk.
Whoops, edited! I got caught out by the description
Yeah, they were too lazy to change the description after copying the code.