New Softwares USB Secure : lets you password protect your USB drives, thumb drives, external drives and memory cards. Protection is PC independent and does not require installation or administrative rights on the other end. You can unprotect your data by entering the password again. Works in all versions of Windows.
With usb access control your USB flash drives and all other external storage devices can be very easily password protected. An easy to use setup program will guide you to put the program on your USB drive. It can automatically detect all such drives currently plugged into your PC. After installing simply run the software, and set and confirm a password to protect USB drive and all the data in it.
The main disadvantage of a Persistent Live USB is the security issue. When you boot up a live USB, it boots directly to the desktop. There is no login or any security mechanism to protect secure usb anyone from accessing your data. The live USB is meant for you to test the distro and install it to the hard drive if you like it. It is not meant to be used as a production OS.