Free open-source disk encryption software for Windows , Mac OS X, and Linux

The most powerful open-source disk encryption software TrueCrpt the latest version (download)

What's new in the 6.1a vertion:
October 31, 2008

New features:

Ability to encrypt a non-system partition without losing existing data on the partition. (Windows Vista/2008)

Note: To encrypt a non-system partition in place, click 'Create Volume' > 'Encrypt a non-system partition' > 'Standard volume' > 'Select Device' > 'Encrypt partition in place' and then follow the instructions in the wizard. Please note that this is not supported on Windows XP/2000/2003 as these versions of Windows do not natively support shrinking of a filesystem (the filesystem needs to be shrunk to make space for the volume header and backup header).

Support for security tokens and smart cards (for more information, see section Security Tokens and Smart Cards in chapter Keyfiles).

The TrueCrypt boot loader can be prevented from displaying any texts (by selecting Settings > System Encryption and enabling the option 'Do not show any texts in the pre-boot authentication screen').

The TrueCrypt boot loader can now display a custom message (select Settings > System Encryption and enter the message in the corresponding field) either without any other texts or along with the standard TrueCrypt boot loader texts.

Pre-boot authentication passwords can now be cached in the driver memory, which allows them to be used for mounting of non-system TrueCrypt volumes (select Settings > System Encryption and enable the option 'Cache pre-boot authentication password').

Linux and Mac OS X versions: The ability to mount a Windows system partition encrypted by TrueCrypt and to mount a partition located on a Windows system drive that is fully encrypted by a Windows version of TrueCrypt.