Created by the U.S. Air Force, the Lightweight Portable Security, or LPS, Linux distribution can turn any PC or Mac into a secure communication node. It runs from a CD or USB thumb drive and removes all traces of your activity when you shut it down.
A variation of OpenSuse, NetSecl, like BackTrack, was built for use in penetration testing situations.
It's not a full operating system, but the SELinux projects has added access control capabilities to the Linux kernel. These features are incorporated into many other Linux distributions, including many of the most popular, like Red Hat and Fedora.
Another privacy-focused Linux distribution, Tails is short for "The Amnesic Incognito Live System." Like Whonix, it leverages Tor and Debian, and it uses encryption tools to protect your files and communications. It runs from a live DVD or USB drive so that you can protect yourself no matter what system you're on.
Based on Virtual Box, Debian GNU/Linux and Tor, Whonix is designed to be a fully anonymous operating system that offers exceptional security and privacy protection. It claims to make IP and DNS leaks impossible.
Every network admin needs a password cracker in his or her arsenal for those times when passwords aren't recoverable any other way. Developed by the people who invented rainbow tables, Ophcrack can use that method or brute force to find unknown passwords. Operating System: Windows, Linux.
66. John the Ripper
John the Ripper is a fast password cracker that relies lists of common passwords in various languages. In addition to the official community version, it also comes in a community-enhanced version, which supports many more ciphers and hashing techniques, or a pro version, which is customized for various OSes and is easier to install and use. Operating System: Windows, Linux, OS X.
As you might guess from the name, this cracker specifically focuses on retrieving passwords and content from PDF files. It runs from the command line and uses both brute force and list-based cracking techniques. Operating System: Linux, Unix.
Using the same password over and over is asking for trouble. Instead, try KeePass. It generates strong passwords for you and stores all your passwords in an encrypted database, so all you have to remember is one master password. Operating System: Windows.
Originally developed as a Linux fork of KeePass, this password safe is very similar to the KeePass. It now supports OS X and some versions of Windows, as well as Linux. Operating System: Windows, Linux, OS X.
70. Password Safe
This app boasts over a million downloads and very fast installation. Like KeePass, it remembers your passwords for you and keeps them secure in an encrypted database. Operating System: Windows.
This award-winning utility supports SFTP, FTPS and SCP protocols for secure file transfer, as well as regular FTP when security isn't required. It includes two different styles of graphic interface, or it can run from the command line. Operating System: Windows.
Like WinSCP, FileZilla supports all the standard file transfer protocols. In addition to the multi-platform client version, it also comes in a Windows-only server version. Operating System: Windows, Linux, OS X.
Whether you use Firefox, Chrome or Internet Explorer, Nixory erases malicious tracking cookies from your browser. Note that you'll need to use it alongside other security software because it only erases tracking cookies and doesn't block viruses or other types of malware. Operating System: OS Independent.
WiKID offers simple, software-based two-factor authentication solutions for enterprises. In addition to the free community version, it also comes in a paid enterprise version that includes some proprietary code. Operating System: OS Independent.
This network content filtering tool uses phrase matching, PICS filtering and URL filtering to help block objectionable content. Recently, a new maintainer took over this project, so it is once again getting patches and updates. Operating System: Linux, OS X.