Festplattenverschlüsselung

http://www.truecrypt.org/

Free open-source disk encryption software for Windows XP/2000/2003 and Linux

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 device.
* 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 – more information may be found here).
2) No TrueCrypt 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).