14.2 Using GnuPG
File handling:
$ gpg [options] command [args]
$ gpg {--armor|-a} {--sign|-s} file # sign file into a text file.asc
$ gpg --clearsign file # clear-sign message
$ gpg --clearsign --not-dash-escaped patchfile # clear-sign patchfile
$ gpg --verify file # verify clear-signed file
$ gpg -o file.sig {-b|--detach-sig} file # create detached signature
$ gpg --verify file.sig file # verify file with file.sig
$ gpg -o crypt_file {--recipient|-r} name {--encrypt|-e} file
# public-key encryption intended for name
$ gpg -o crypt_file {--symmetric|-c} file # symmetric encryption
$ gpg -o file --decrypt crypt_file # decryption
