Some useful resources for OpenPGP

The following is a collection of various pointers to freely available online resources on OpenPGP. I plan to keep that collection reasonably up-to-date, do not hesitate to contact me if you are aware of a resources not listed here or if you notice a broken link (e.g. to a resource that is no longer available).

OpenPGP specification documents

• RFC 4880, the current version of the standard.
• RFC 5581, which adds support for the Camellia cipher.
• RFC 6637, which adds support for ECC-based public key algorithms.
• RFC 7929, describing the publication of public keys in the DNS.
• draft-ietf-openpgp-rfc4880bis, the draft for the next revision of the OpenPGP format.
• draft-koch-openpgp-webkey-service, the draft describing the Webkey Directory Service.
• OpenPGP Card 3.4, the last version of the specification for the OpenPGP smartcard.

OpenPGP implementations

• GnuPG, the reference C implementation.
• RNP, another C implementation.
• Sequoia-PGP, a Rust implementation.
• OpenPGP.js, a JavaScript implementation.
• hOpenPGP, a Haskell implementation.
• Bouncy Castle, a Java/C# cryptographic library including an OpenPGP implementation.
• Cryptlib, a C cryptographic library including an OpenPGP implementation.

Documentations

• OpenPGP.org, a frontpage for the whole OpenPGP ecosystem; plenty of other resources linked from there.
• CompariTech’s series of articles on encryption, including:
  • How to encrypt email?
  • What is PGP encryption?
  • A Beginner’s Guide to Cryptography
  • Public-key cryptography
  (Courtesy of Kiera Winters)

Services

• The status page for the SKS keyservers network.
• keys.openpgp.org, a validating keyserver.

30 July 2020