FreeOTFE is a free, open source windows mobilw app to achieve “on-the-fly” transparent disk encryption on your mobile device and they also have a PC counterpart. Using this software, you can create one or more “virtual disks” on your PC/PDA. These disks operate exactly like a normal disk, with the exception that anything written to one of them is transparently, and securely, encrypted before being stored on to the disk drive. The app provides a wide array of encryption algorithm to choose from. Full Feature List

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