If you know a cryptography newsgroup that isn't listed here, please e-mail me about it.
The newsgroup that inspired this site, alt.security.keydist was newgrouped by Jonathan Haas on 27 February 1993, and is intended for the distribution of public keys. The newsgroup is currently close to dead, but I still post the FAQ monthly.
This newsgroup was newgrouped by PGP developer Peter Gutmann on 15 September 1992. Still the highest volume encryption newsgroup.
This newsgroup was newgrouped by -=Xenon=- <email@example.com> (that's a false address) on 25 December 1994. It was almost immediately rmgrouped due to lack of discussion on alt.config, resulting in truly pitiful propagation. Messages posted to alt.security.pgp.patches probably won't leave the site they're posted from. For all intents and purposes, this newsgroup doesn't really exist.
This newsgroup was newgrouped by Marc VanHeynigen on 16 December 1992, nominally for discussing RIPEM, but it tends to get swamped by crossposts from other cryptography groups. Now that development of RIPEM has ended, alt.security.ripem often goes for a year or more without a on-charter posting.
Created to move PGP discussion out of alt.* and into the Big 8 hiearchies. This newsgroup has been rmgrouped and superseded by the next five groups.
A moderated newsgroup created for the posting of PGP-related annoucements. Officially defunct.
A general discussion group for PGP users. Mostly consists of cross-posts to its busier ancestor, alt.security.keydist.
For discussions of the technical aspects (formats and programming) of PGP.
Created to give PGP users a place to test posting PGP- signed and encrypted messages. If you post a message here, somebody will probably post a followup telling you if it worked.
Originally created for customers of British ISP Demon Internet to distribute public keys. Seems to be overrun by teenagers posting registration keys for cracked computer games.
A French-language newsgroup for discussing cryptography.
This newsgroup is defunct. It was actually a gatewayed version of mailing list used by many members of the (also now defunct) Privacy-Enhanced Electronic Mail Working Group of the IETF. In its prime, info.pem-dev consisted mostly of technical discussions of PEM formats and public key infratructures.
An Italian-language newsgroup for PGP users.
Possibly the oldest cryptography newsgroup, sci.crypt focuses on discussion of the technical aspects of cryptography. It occasionally get overrun with conversations better placed in a politics group, so a lot of the serious cryptographers have defected to the next group.
A moderated newsgroup, sci.crypt.research was newgrouped based on a charter by Peter Gutmann.