Signify is a toool to create and verify signatures on files.
Homepage: https://github.com/aperezdc/signify
As an alternative to GnuPG (GPG), it is a single-purpose tool originally designed to fill some needs at OpenBSD. It is focused solely on signatures and doesn’t do encryption or descryption. It can make for a simpler approach when that is all that’s needed.
A similar tool for encryption/decryption is Age (Encryption).
Links to this note
GnuPG (also known by its command name, gpg) is a tool primarily for public key Encryption and cryptographic authentication.
Sometimes, one wants to verify the integrity and authenticity of a Filespooler job file before processing it.
Anything that uses encryption to keep content away from spying eyes.