Security

Authentication using X.509v3 certificates with isakmpd.
How to use X.509v3 certificates for authentication with OpenBSD's isakmpd.
http://hem.passagen.se/hojg/isakmpd/

Cryptography in OpenBSD: An Overview
Whitepaper presented at USENIX 99 by OpenBSD developers Theo de Raadt, Niklas Hallqvist, Artur Grabowski, Angelo D. Keromytis, and Niels Provos discussing the cryptography employed in OpenBSD.
http://www.usenix.org/events/usenix99/deraadt.html

Dealing with Public Ethernet Jacks
Whitepaper from the University of Alberta on using OpenBSD to block unauthorized users on unprotected Ethernet jacks.
http://www.ualberta.ca/~beck/authgw.html

Design and Performance of the OpenBSD Stateful Packet Filter (pf)
This paper from Usenix 2002 describes the design of the new OpenBSD packet filter (pf) and compares performance of stateful vs. stateless filtering.
http://www.benzedrine.cx/pf-paper.html

Future-Adaptable Password Scheme
Whitepaper by OpenBSD developers Niels Provos and David Mazières discussing ways of building systems in which password security keeps up with hardware speeds.
http://www.usenix.org/events/usenix99/provos.html

Hardening OpenBSD Internet Servers
Tutorial on hardening and improving security on OpenBSD systems.
http://geodsoft.com/howto/harden/

IP Filter HOWTO
Usage guide for the IP Filter firewall software formerly included with OpenBSD.
http://www.obfuscation.org/ipf/

IPSEC Bridging Under OpenBSD
'Plugging holes with your fingers' - a guide to configuring IPSEC in OpenBSD.
http://default.co.yu/~bc/docs/ipsec_bridging-1.txt

IPSec HOWTO [Linux, OpenBSD, PGPNet]
Configuration document on IPSec interoperations for Linux, OpenBSD and PGPNet.
http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html

OpenBSD Packet Filter (pf)
Information regarding history and design of the new OpenBSD packet filter (pf).
http://www.benzedrine.cx/pf.html

PGPnet & OpenBSD
How to configure isakmpd on OpenBSD to use the PGPnet client.
http://www.allard.nu/openbsd/

Secure Internet Servers/Firewalls with OpenBSD
Outline notes for the half-day tutorial presented at the O'Reilly Open Source Conference in Monterey, California on July 17, 2000.
http://www.openbsd.org/papers/oreilly2000/

S/Key configuration on OpenBSD
How to configure and use the S/Key 'one-time password' scheme on OpenBSD.
http://tika.arnholm.nu/skey.html

Veghead's Guide to OpenBSD Firewalls
Introductory guide to implementing a firewall using OpenBSD.
http://www.fatsquirrel.org/veghead/wot/openbsd.html