flash drives can hold a large amount of information and they are used worldwide. many users store information on them that is personal, or that should be protected. for this reason, more and more flash drives offer biometrics or encryption to control the access to this data. users can install passwords on to their flash drives so that when a user tries to open it, the computer prompts the user, to enter a password before they can begin using the device. there are a number of free and open source programs which can be used to encrypt data including truecrypt, pgpdisk and freeotfe. these programs have proved useful in securing data on flash drives.