The ultimate in USB flash drive security can take many forms. Some manufacturers use biometric fingerprint readers or combination locks to secure data. Others rely on software to encrypt sensitive information, or Internet-based tracking systems to enable remote deletion of the drive's memory in case of theft. Many of these drives end up being dismissed by reviewers as overkill for the average user. Secure USB flash drives tend to be much slower and more expensive than their unsecured counterparts; if you don't need hardcore security, you may want to opt for a standard drive.
Depending on how much security you need, you can select a variety of levels of protection. For basic security, many reviewers recommend the Corsair Flash Padlock 2, which at an estimated $45 for 16 GB is a reasonably priced entry in the often exorbitant price ranges for secure USB keys. It encrypts data and has external buttons that allow you to enter a personal identification number of four to 10 digits to unlock the device. Like most secure USB flash drives, it uses the slower USB 2.0 standard.
The bargain in the basic user security area is the Kingston DataTraveler Locker+, which retails for $26 for 16 GB. Several sites give it positive reviews, including more than 85 users at Amazon.com, where it earns an average of 4.5 out of 5 stars. It lacks the Padlock's external security, but data is encrypted and it comes with a 5-year warranty.
For users who need more serious protection, PCMag.com rates the Imation Personal S200 flash drive powered by IronKey (*Est. $245 for 16 GB) (formerly IronKey Personal S200) at 4 out of 5 points for being tops in security. They note that the tough metal exterior and military-grade security features -- for example, entering 10 incorrect passwords in a row causes the drive to self-destruct -- essentially guarantees the best security for your computer files.
The S200 also has an improved password-management system, an issue with the earlier version. The-Gadgeteer.com notes that the Personal S200 was on its release the only flash drive to have attained Level 3 FIPS 140-2 (Federal Information Processing Standard), and ThinkGeek.com says the Imation/IronKey S200 has been used by the U.S. military in Afghanistan. All this security comes with the heftiest price tag of any USB flash drive covered in this report. IronKey drives are among the only commonly available USB flash drives on the market to meet the FIPS Level 3 standard even now. That's important, because it's required for military and many government uses. A much larger collection of drives meet FIPS Level 2 standards, which do not protect against hardware tampering.
While the Imation/IronKey S200 (and the Imation/IronKey D200, which is also positively reviewed) are still in stock and sold by the manufacturer and common online vendors, IronKey's secure USB flash drive business was recently purchased by Imation Mobile Security, one of its major competitors.