Avoid storing critical or extremely sensitive data on USB sticks as they're not as reliable as SSDs or regular hard drives. Locking and securing a USB stick is a temporary solution to data safety.
A common pitfall associated with securing USB sticks is the loss of passwords. Sometimes, the owner forgets the password he used to lock the stick. This can be disastrous if the data is important.
USB Secure - With a stunning interface, this application is one of the best candidates to secure your USB sticks. There are no complex multiple steps for securing your sensitive data. Simple one-click operation locks your USB drive in a secure manner. Once configured, it doesn't need installation on external devices on which a secure USB drive is going to be used. It also has a powerful anti-theft feature to ensure your most sensitive data is not leaked at all. Through its virtual drive interface, you can easily work on protected information without any hassle. Do once give this application a try.
USB Locker - As the name implies, use this handy application to securely lock your USB sticks. Apart from USB drives, it can also lock other types of external flash storage devices. It uses multiple layers of encryption to harden the security of the drive. In case, you forget the locking password, you can use the application's master password to initiate the recovery process. If someone tries to steal your data through unsuccessful penetration attempts, the program can detect it easily. It can work on all operating systems without any issues and ensures you can work with your data almost anywhere.
GiliSoft USB Stick Encryption - This excellent USB drive locking program comes in both 32-bit and 64-bit variants with support of wide range of Windows platforms. Through it, you can easily divide your USB storage space into two distinct parts. One is the publicly accessible space while the other one is totally secure and protected from unauthorized access. This is yet another USB locking application with an excellent interface. Due to its military grade protection with multiple layers, your data is safe even if it is stolen. I've tested this application both with a USB drive and microSD card.
EasyLock - This application can work on all popular platforms like Windows, Mac and Linux. It securely encrypts USB storage space to lock the information preventing unauthorized access. Instead of point and click operations, one can take advantage of its drag and drop support to quickly lock and encrypt multiple files in one go. Its unique hacker safe technology automatically erases the secured data if specific numbers of incorrect tries are made to retrieve the information. I've thoroughly tested this application on a Linux machine with a regular USB stick and found it extremely good.
DriveLock - This powerful USB drive locking application is more suited for business professionals and companies. It uses a centralized device management interface to secure external storage devices. One can also take advantage of its cloud backup service to keep a copy of secured information at a remote location. It also has a client end application for managing secured devices at the end user premises. Data syncing feature ensures all the encrypted information is up-to-date in multiple locations. If your business regularly shares sensitive information with clients, use this application.
SanDisk SecureAccess - If you have a SanDisk USB flash drive, this software is made just for you. It can be used to easily create a password-protected folder on your USB stick. Apart from military-grade encryption, it also supports drag 'n' drop feature to easily transfer files in your protected folder. One can also edit and restore files stored in the protected folder easily without any need to extracting them first. This application can work both on Windows and Mac systems. It also has a handy timeout feature to prevent accidental access of information while using shared or public computers.
Flash Drive Security - You can use this application to protect all kinds of flash storage devices. The locking process is dead simple and just requires clicking a button. The same process is reversed for the unlocking action making it one of the most user-friendly USB locking programs. It also includes several other useful utilities to keep your storage drives in good and healthy condition. It also packs and hides all the locked and encrypted information so that they're not visible through regular file browsers. It's one of my preferred programs when it comes to securing and locking USB flash drives.