GNU privacy guard - cryptographic agent

 GnuPG is GNU's tool for secure communication and data storage.
 It can be used to encrypt data and to create digital signatures.
 It includes an advanced key management facility and is compliant
 with the proposed OpenPGP Internet standard as described in RFC4880.
 .
 This package contains the agent program gpg-agent which handles all
 secret key material for OpenPGP and S/MIME use. The agent also
 provides a passphrase cache, which is used by pre-2.1 versions of
 GnuPG for OpenPGP operations. Without this package, trying to do
 secret-key operations with any part of the modern GnuPG suite will
 fail.