Random links collated whilst surfing for a PGP API in Java...

JCE

Java Cryptography Extension -- doesn't seem to support PGP out of the box, basically for legal (export) reasons, but there may be other service provider implementations lurking out there...

The Cryptix JCE implementation has some form of "openpgp" support. This is a clean-room implementation of JCE. There's also Cryptix PGP. This is still in alpha and has a good feature list, although key servers aren't currently supported. Last Alpha was released on 5th Feb 2003.

SlimPGP seems to offer the desired functionality as it provides a simple command line interface that can be used to create OpenPGP keys, encrypt/decrypt files and digital sign/verify texts.

BouncyCastle.org (redirected there from openjce.org). Another clean-room JCE implementation. No sign of PGP. Although the Hush Encryption Engine includes an OpenPGP implementation designed to work with this API.

pgpjava hooks into PGP using JNI. I'd rather avoid this if possible. I'd really like a pure Java API as deployment will be less of a PITA.

Related

• PGP Message Exchange formats (RFC 1991)
• Open PGP Message Format (RFC 2440)
• Nice description of PGP (hey I don't use this stuff everyday you know! :)