# External resources

[OpenPGP version 6 draft specification](https://datatracker.ietf.org/doc/draft-ietf-openpgp-crypto-refresh/) draft-ietf-openpgp-crypto-refresh [2023]

[RFC4880](https://www.rfc-editor.org/rfc/rfc4880.html) OpenPGP Message Format [2007], specifies OpenPGP version 4


## Web of Trust

[PGP Web of Trust: Core Concepts Behind Trusted Communication](https://www.linux.com/training-tutorials/pgp-web-trust-core-concepts-behind-trusted-communication/),
[PGP Web of Trust: Delegated Trust and Keyservers](https://web.archive.org/web/20210417113254/https://www.linuxfoundation.org/blog/pgp-web-of-trust-delegated-trust-and-keyservers/) [Konstantin Ryabitsev, 2014]

[OpenPGP Web of Trust](https://sequoia-pgp.gitlab.io/sequoia-wot/) [Neal Walfield, 2022];
implementation: <https://gitlab.com/sequoia-pgp/sequoia-wot/>.

## GnuPG

[An Advanced Introduction to GnuPG](https://gnupg.org/ftp/people/neal/an-advanced-introduction-to-gnupg/openpgp/openpgp.pdf) [Neal Walfield, 2017]