Free Open Source USB Encryption Software Utility: TrueCryptTrueCrypt has just what you are looking for, provided you are looking for free USB flash drive encryption software utilities.
- Level 1: Hidden volumes. This is where a volume is created within another volume by TrueCrypt. The upper level (the one seen by a person forcing you to get the content) is filled with random data, so you can show them “Look man, there’s nothing there!”
- Level 2: A volume appears to consist of nothing more than random data, no signature or typology what-so-ever. Therefore, it is impossible to prove that a file, a partition or a device has been encrypted.