agree with Flatiron suggestion. Get truecypt, i've encrypted my hdd's with it so it should all go well with encrypting that flash drive. Pretty easy and simple to use, think you will like it.
My Computer
Computer type
PC/Desktop
Computer Manufacturer/Model Number
custom build
OS
Windows 10 64bit
CPU
AMD Phenom II X4 925 (Deneb)(2.8GHz) OC 3.4GHz
Motherboard
M5A78L-MLX Plus
Memory
Corsair Vengeance DDR3 4GBX2 (8192MB)
Graphics Card(s)
XFX HD 6870 1GB (OC)- 940MHz core, mem 1150MHz
Monitor(s) Displays
Vizio 26' 1920x1080 / Acer 1336x768
Screen Resolution
1920x1080 60Hz /1336x768
Hard Drives
Kingston Digital 60GB SSDNow V300/500gb HDD Western Digital 7200rpm (/WD 160GB HDD 7200rpm