The resulting public keys may be exchanged with other users in a variety of ways, such as Internet key servers.
GnuPG encrypts messages using asymmetric key pairs individually generated by GnuPG users. The GnuPG 1.x series uses an integrated cryptographic library, while the GnuPG 2.x series replaces this with Libgcrypt. This mode of operation is part of the OpenPGP standard and has been part of PGP from its first version. GnuPG is a hybrid-encryption software program because it uses a combination of conventional symmetric-key cryptography for speed, and public-key cryptography for ease of secure key exchange, typically by using the recipient's public key to encrypt a session key which is used only once. GnuPG is part of the GNU Project and received major funding from the German government in 1999. Modern versions of PGP are interoperable with GnuPG and other OpenPGP-compliant systems. It is compliant with RFC 4880, the IETF standards-track specification of OpenPGP. GNU Privacy Guard ( GnuPG or GPG) is a free-software replacement for Symantec's PGP cryptographic software suite. Microsoft Windows, macOS, RISC OS, Android, Linux
