TrueCrypt - Free Open-Source On-The-Fly Disk Encryption Software for Windows 7/Vista/XP, Mac OS X and Linux

T r u e C r y p t

Free open-source disk encryption software for Windows 7/Vista/XP, Mac OS X, and Linux

Main Features:

Creates a virtual encrypted disk within a file and mounts it as a real disk. Encrypts an entire partition or storage device such as USB flash drive or hard drive. Encrypts a partition or drive where Windows is installed (pre-boot authentication). Encryption is automatic, real-time (on-the-fly) and transparent. Parallelization and pipelining allow data to be read and written as fast as if the drive was not encrypted. Encryption can be hardware-accelerated on modern processors. Provides plausible deniability, in case an adversary forces you to reveal the password: Hidden volume (steganography) and hidden operating system. More information about the features of TrueCrypt may be found in the documentation. What is new in TrueCrypt 7.0a

Go there...
http://www.truecrypt.org/

The Fedora 13 rpmfusion nonfree Repo also has realcrypt which is based on Truecrypt.

Based on TrueCrypt, freely available at http://www.truecrypt.org/.
realcrypt is mainly just a rebrand to allow for modifications to take place, functionality remains all the same.
Main Features:
* Creates a virtual encrypted disk within a file and mounts it as a real disk.
* Encrypts an entire hard disk partition or a storage device such as USB flash drive.
* Encryption is automatic, real-time (on-the-fly) and transparent.
* Provides two levels of plausible deniability, in case an adversary forces you to reveal the password: 1) Hidden volume (steganography). 2) No RealCrypt volume can be identified (volumes cannot be distinguished from random data).
* Encryption algorithms: AES-256, Blowfish (448-bit key), CAST5, Serpent, Triple DES, and Twofish. Mode of operation: LRW (CBC supported as legacy).

I'm trying it out today...

Don