iStorage Diskgenie

The Diskgenie is a portable hard disk with a number keypad on one side.

This is used to enter a code, without which the files on the disk cannot be accessed. In fact, until the user types the code and presses the unlock key, the computer won’t recognise there’s a disk plugged in at all.

The device uses strong encryption (256-bit AES, for the technically minded) to scramble what’s on its internal disk, so even if someone were to remove it and try to install it in a computer the files would still be safe.

Transfer speeds were not affected by the security process – it was about as fast as a standard USB disk. The device is set up to automatically lock itself if the wrong number is entered a certain number of times – after that, it must be unlocked using a number printed in the manual.

Setting it up was simple – it works just like a standard external disk, and so was changing the security code from the default with which it was supplied.

It connects using USB (the cable is attached to the device) and is available in several sizes (capacities) – the 320GB one we looked at is £128, while a 640GB model is £199 and the smallest 250GB one is £117. Each is roughly twice the price of a standard (un-secured) external hard disk.

This kind of hardware encryption is better and more thorough than using software, though, and there's the advantage that the Diskgenie will work on any USB-enabled computer – using software encryption causes problems when moving from PC to Mac or Linux computers.

Although it's more expensive than a standard hard disk, if you want to make sure your files are secure when you transport them, Diskgenie is a good way to do it.