It’s kind of ironic for an agency whose sole purpose is to spy on others would release a guide to secure one’s system. NSA last month released a list of guide to secure an operating system, but what we are interested most are the guides to Secure RHEL 5. The two guides are called:

1) Hardening Tips for the Red Hat Enterprise Linux 5
http://www.nsa.gov/notices/notic00004.cfm?Address=/snac/os/redhat/rhel5-pamphlet-i731.pdf

2) Guide to the Secure Configuration of Red Hat Enterprise Linux 5
http://www.nsa.gov/notices/notic00004.cfm?Address=/snac/os/redhat/rhel5-guide-i731.pdf

You can see a list of all the guides for RHEL and other operating system’s over here: http://www.nsa.gov/snac/downloads_redhat.cfm?MenuID=scg10.3.1.1

In their own word:

NSA initiatives in enhancing software security cover both proprietary and open source software, and we have successfully used both proprietary and open source models in our research activities. NSA’s work to enhance the security of software is motivated by one simple consideration: use our resources as efficiently as possible to give NSA’s customers the best possible security options in the most widely employed products. The objective of the NSA research program is to develop technologic advances that can be shared with the software development community through a variety of transfer mechanisms. NSA does not favor or promote any specific software product or business model. Rather, NSA is promoting enhanced security.