GnuPG is GNU's tool for secure communication and data storage.

gpgv is a stripped-down version of gnupg which is only able to check signatures. It is smaller than the full-blown gnupg and uses a different (and simpler) way to check that the public keys used to make the signature are trustworthy.

This is a win32 version of gpgv. It's meant to be used by the win32-loader component of Debian-Installer.