Rather than focusing strictly on distributions I thought I’d list some applications that run on Linux which can be useful when configured correctly.
An intrusion detection system that can be remotely monitored using an application called Beltane. Similar to Snort and Suricata tables but with an impressive scalability. Whether you are monitoring one machine or 1000, Samhain is worth investigating as an option.
Granted this isn’t Linux but as BSD has some of the highest security ratings anywhere a BSD router is certainly a worthwhile consideration.
An interesting approach to using virtualization to enhance security. Using a desktop to support an environment where every appliance is in fact in a seperate virtual environment might sound daunting but for security purposes it might be a direction for banks and corporations to consider.
Intruson testing from either a desktop, laptop, virtual, or live environment. Among the most well known distributions and certainly the most popular among companies who specialize in penetration testing.
An Ubuntu based pen testing distribution with an emphasis on privacy. Secure deletion of session data right down to wiping ram on exit, this low resource distribution is sleek and has many built in options for new testers.
Powerful and simple network protocol analyzer. Easily the most recognizable way to visually analyze network traffic.
Offering an array of network protocols from FTP to SSH Filezilla is useful for anyone from website administrators to network testers. One of the best free tools available.
Security can mean many things, and camera monitoring certainly qualifies. Xeoma has a variety of licensing options as well as surveilance via http protocol which allows for remote surveilance of home or office. A win win for the end user, it works seamlessly.