Protected USB storage is a very good idea for keeping mobile data safe. Several USB storage devices are now available with fingerprint scanners to secure data. Trek's ThumbDrive Swipe is another, but with a couple of interesting twists.

The most obvious difference is that the ThumbDrive Swipe does not use a standard fingerprint sensor, but requires the user to slide his finger over a narrow strip which scans the print in passing. This makes it impossible for an attacker to "lift" a print off the device. The sensor is concealed in a sliding housing for protection, making the whole package a neat little unit not much bigger than standard USB memory devices.

Another difference is that the drive does not require a driver. Instead a login executable resides in the unencrypted ("public") area of the drive, which when run opens a screen with login and management options. An identical executable (just renamed "logout") resides in the encrypted part of the drive and is then used to disconnect. Software is provided on the device for Windows 2000 and XP, and versions for 95/98 and (we were delighted to see) for Mac OS X are available for download from the Trek website.

When run for the first time, the login software asks for master registration, at which point the admin username, fingerprint and optional password is set. This went well enough, though it take a lot of practice scans to get the knack of using the scanner. In fact we never did get it to read a finger, finding it instead much more successful in scanning thumbprints, which worked just fine. We do wonder if some users may find it frustrating to master. And once the master registration is complete, you cannot change your mind about wanting a password or not, nor can the master fingerprint be changed.

Up to three additional users can be registered, and the system automatically detects which user is present when the finger is scanned. By now we'd got the knack of scanning thumbs, and enrolling other users was quick and easy.

The split between encrypted and public can be set to any size, though at least 2mb must be public. This is because when the drive reformats to create the partitions, it rewrites the login application too (and the logout one, if you have assigned any encrypted space), which is a nice touch. The master user must login to resize the partitions. The software started feeling fiddly at this point – because the login and logout executables are the same, if it detects an existing login, the software offers only the option to logout. So you have to logout and then rerun the application in order to get to the user registration and repartitioning options.

Logging in is quick and easy, but the sensor dialogue once opened provides no way to exit without logging in. Despite using a standalone application and not a driver to access the drive, I/O performance did not seem affected at all.

No documentation is provided in the box, but detailed PDFs are to be found on the company's website. We'd have liked the URL for that to be clearly marked on the packaging: not all users would have the patience or web savvy to trawl around a site looking for drivers and docs.

We like the ThumbDrive Swipe a lot. The software niggles are minor and the sensor, though it took a bit of getting used to, works very well. You are paying a premium for the biometric component, but we think it is well worth it.