Despite years of constant high-tech innovation, the password remains a fundamental feature of most networks. Various tools let you consolidate, encrypt, sanitize, and synchronize passwords, but unless your company invests heavily in smart cards or other new age technologies, you'll eventually have to log in somewhere. This month we look at some techniques for supporting, securing, and simplifying user authentication in Linux.

Our first article examines some tools for authenticating users with one-time passwords. You'll learn why many organizations prefer passwords that change with every login. We then zero in for a look at OPIE and OTPW – a pair of open source solutions for one-time password authentication.

Many Linux users would rather not even think about Microsoft, but part of our mission has always been to let readers know about free, open source tools for easy integration with proprietary technologies. Our next article describes how Samba's Windbind service lets Linux clients participate in Microsoft's Active Directory environments.

We'll also discuss some options for creating password-protected pages for your website. We'll look at how the Apache web server handles authentication, we'll examine authentication alternatives based on SQL and LDAP, we'll show you how to create a custom authentication solution in Perl.

The final article describes how to use the OpenID service as a single authentication system for multiple web accounts. Read on for more on some great techniques for managing user identities in Linux.