the "modern" series (i.e. since GnuPG 2.1). Algorithms As of 2.3 or 2.2 versions, GnuPG supports the following algorithms: Public key RSA, ElGamal, DSA, ECDH (cv25519, cv448, nistp256, nistp384, nistp521, brainpoolP256r1, brainpoolP384r1, brainpoolP512r1, secp256k1), ECDSA (nistp256, nistp384, nistp521, brainpoolP256r1, brainpoolP384r1, brainpoolP512r1, secp256k1), EdDSA (ed25519, ed448) Cipher 3DES, IDEA (for backward compatibility), CAST5, Blowfish, Twofish, AES-128, AES-192, AES-256, Camellia-128, -192 and -256 Hash MD5, SHA-1, RIPEMD-160, SHA-256, SHA-384, SHA-512, SHA-224 Compression Uncompressed, ZIP, ZLIB, BZIP2 History GnuPG was initially developed by Werner Koch. The first production version, version 1.0.0, was released on September 7, 1999, almost two years after the first GnuPG release (version 0.0.0). The German Federal Ministry of Economics and Technology funded the documentation and the port to Microsoft Windows in 2000. GnuPG is a system compliant to the OpenPGP standard, thus the history of OpenPGP is of importance; it was designed to interoperate with PGP, an email encryption program initially designed and developed by Phil Zimmermann. On February 7, 2014, a GnuPG crowdfunding effort closed, raising €36,732 for a new Web site and infrastructure improvements. Branches Since the release of a stable GnuPG 2.3, starting with version 2.3.3 in October 2021, three stable branches of GnuPG are actively maintained: A "stable branch", which currently is (as of 2021) the 2.3 branch. A "LTS (long-term support) branch", which currently is (as of 2021) the 2.2 branch (which was formerly called "modern branch", in comparison to the 2.0 branch). The old "legacy branch" (formerly called "classic branch"), which is and will stay the 1.4 branch. Before GnuPG 2.3, two stable branches of GnuPG were actively maintained: "Modern" (2.2), with numerous new features, such as elliptic curve cryptography, compared to the former "stable" (2.0) branch, which it replaced with the release of GnuPG 2.2.0 on August 28, 2017. It was initially released on November 6, 2014. "Classic" (1.4), the very old, but still maintained stand-alone version, most suitable for outdated or embedded platforms. Initially released on December 16, 2004. Different GnuPG 2.x versions (e.g. from the 2.2 and 2.0 branches) cannot be installed at the same time. However, it is possible to install a "classic" GnuPG version (i.e. from the 1.4 branch) along with any GnuPG 2.x version. Before the release of GnuPG 2.2 ("modern"), the now deprecated "stable" branch (2.0) was recommended for general use, initially released on November 13, 2006. This branch reached its end-of-life on December 31, 2017;