PGP-Users Mailing List Home Page
- Home page of the PGP-Users Mailing List and many good PGP related links.
- http://www.cryptorights.org/lists/pgp-users/

PGP Web-of-trust analysis
- Statistics about the position of all keys within the web-of-trust. It calculates the MSD and the rank of the key over time.
- http://t-butter.de/gpg

PGP pathfinder and key statistics
- Lookup the statistics of your PGP key. The pathfinder finds trust paths between your key and some other key in the PGP web of trust.
- http://www.cs.uu.nl/people/henkp/henkp/pgp/pathfinder/

Phil Zimmermann's Home Page
- Phil Zimmermann is the original creator of PGP and a founder of PGP, Inc. This site offers historical PGP background and current resource links.
- http://www.philzimmermann.com/EN/background/index.html

Robot CA
- It signs PGP keys automatically. The point is only to verify the email address on the key, not to verify the identity of the email address's owner. Given a PGP key signed by a Robot CA, the user knows that the key really does belong to the email address
- http://www.toehold.com/robotca/

DSJ Networks PGP Resources
- A superior collection of PGP annotated resources and links to include books, tutorials, utilities, news, and articles.
- http://www.dsj.net/pgp/resources.html

Open PGP Alliance
- The OpenPGP Alliance is a growing group of companies and other organizations that are implementers of the OpenPGP standard. The Alliance works to facilitate technical interoperability and marketing synergy between OpenPGP implementations.
- http://openpgp.org

Diceware Passphrase
- A way to choose a secure Passphrase for use with PGP.
- http://world.std.com/~reinhold/diceware.page.html

PGP Digital Timestamping Service
- Stamper is a free digital timestamping service which uses PGP and operates via Internet email.
- http://www.itconsult.co.uk/stamper.htm

IETF OpenPGP Working Group
- Provides IETF standards for the algorithms and formats of PGP processed objects as well as providing the MIME framework for exchanging them via e-mail or other transport protocols.
- http://www.ietf.org/html.charters/openpgp-charter.html