SecurStick - Free portable application that lets you carry encrypted files on your USB drive.
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
Rohos Disk Encryption - Rohos Disk Encryption is not about encrypting the some USB sticks only, rather it contains the some additional features and functions as well to deliver the extra encryption systems for your PC.
Microsoft BitLocker - BitLocker is a full disk encryption feature included with Windows Vista and later.
USBCrypt - USBCrypt is the name of a highly advanced encryption software that delivers the two-step verification system to the USB holders to protect their data from unauthorized and unwanted access.
Symantec Data Loss Prevention - Fully protect your data with the comprehensive detection technologies and unified policies of Symantec's industry leading Data Loss Prevention (DLP).