OpenPGP

OpenPGP is a standardized data format for encrypted and digitally signed data. It also specifies the format of certificates, commonly referred to as "keys".

It is based on the format introduced by Pretty Good Privacy (PGP) 5 and is standardized in RFC 4880. RFC 5581 added Camellia (another symmetric cipher algorithm). RFC 6637 added Elliptic Curve Cryptography to OpenPGP. However, these extensions are explicitly specified as "optional". An OpenPGP-compliant application is therefore not forced to implement these two extensions. The practical advantage of elliptic curve cryptography is the comparatively small key size for the same encryption strength.

Note: The redlinks are brought back upon an argument presented by Lgillis, which I kind of agree with. Copied over from their previous edit, see page history:

We're not going to get anywhere like this. The [[red shining links]] are supposed to attract new users here - a link to external pages pulls users away from I2P, which is the opposite of what is supposed to be achieved. This example should clarify that.