TrueEncrypt is a free open Source Encryption Software written in C++ programming language. If you haven't used TrueCrypt before but need to protect confidential information and documents then I can totally propose to use this Free Software. The latest version has the ability to encrypt the whole drive on windows operating system. So without the password (which you set to encrypt the drive), you can not run your windows operating system.
This free open source software is available for windows including (XP and Vista). It is also available for Linux and Mac OS X. Currently the software uses three types of encryption techniques. They are Whirlpool, SHA-512, RIPEMD-160.
One of the features of the software is to encrypt/decrypt the files on the fly. It means that the software can encrypt or decrypt the files in real time. An example could be a video file or a program setup file. When user double clicks on the files to run it, it is decrypted at real time and the program is run from the RAM. I have never seen any software before. I would suggest you to read through the Documentation section before you download the free program.
Here are the links you would be interested in.
- Link to download the TrueCrypt Encryption program
- Download the Source Code entirely written in (C, C++ and Assembly)
- Download other free C and C++ programs.