gpg

GNU Privacy Guard. More information: https://gnupg.org.

Sign doc.txt without encryption (writes output to doc.txt.asc):

gpg --clearsign {{doc.txt}}

Encrypt doc.txt for alice@example.com (output to doc.txt.gpg):

gpg --encrypt --recipient {{alice@example.com}} {{doc.txt}}

Encrypt doc.txt with only a passphrase (output to doc.txt.gpg):

gpg --symmetric {{doc.txt}}

Decrypt doc.txt.gpg (output to stdout):

gpg --decrypt {{doc.txt.gpg}}

Import a public key:

gpg --import {{public.gpg}}

Export public key for alice@example.com (output to stdout):

gpg --export --armor {{alice@example.com}}

Export private key for alice@example.com (output to stdout):

gpg --export-secret-keys --armor {{alice@example.com}}