TrueCrypt is being audited by a team of experts to assess if it could be easily exploited and cracked. Free, open-source and cross-platform encryption program available for Windows, OSX and Linux that can be used to encrypt individual folders or encrypt entire hard drive partitions including the system partition. The program is also capable to do some amazing things, such as can create a hidden operating system on a computer, essentially an OS within an OS where users can keep their most secret files.
Source: https://thehackernews.com/2014/04/truecrypt-is-secure-encryption-tool_15.html