As the USB memory key plummets rapidly towards mere commodity status, the holder of the flash drive patent, M-Systems, has at long last added intelligence to what is otherwise a dumb hardware platform. Smart ‘DiskOnKey’ storage now lets you run apps from your USB device and one of the first devices to exploit this new capability is the disgo Xkey. This diminutive gadget (60mm by 20mm in diameter) lets you connect to your Exchange Server account from any Internet-enabled PC, effectively turning it into a corporate workstation.

Once connected, the Xkey runs a full Exchange client, a database for securely storing Exchange data and a synchronization engine, so the host system doesn’t need to run an Outlook client. Xkey synchronises directly with the Exchange server behind the firewall using HTTP/HTTPS.

The Xkey is a bit larger than your run of the mill USB memory key but that’s because it packs some other hardware in there, including a 50MHz 32-bit ARM-7 CPU, ROM and RAM, a data compression engine, a cryptographic engine, a relational database (!) and a Java application server. As well as a self-contained Exchange client, the Xkey also operates as a common or garden USB memory key, either 256MB or 512MB, depending on model. This is not accessible until you log in and so the data kept here is well protected.

The Xkey couldn’t be simpler to use – you simply plug it in to a spare USB port and a wizard steps you through configuring it, selecting a password, entering your mail server details and so on. It really needs a USB 2.0 port as it can take a minute or two to login, install its anti-spyware software and connect to your firm’s email server. When it does, your browser then opens and a version of Outlook Web Access (OWA) pops up. It then synchronises with your company’s Exchange server and gets your latest emails over an encrypted SSL VPN link, but if it’s offline then you still have access to all of your data.

A large orange LED indicates network traffic activity. Online help is well-presented, clear and thorough.

Not surprisingly, the Xkey incorporates some stringent security features as standard. It starts when you login – get the password wrong ten times and you need to reformat the Xkey. It won’t accept feeble passwords either – they have to contain a mix of upper and lower case letters and numbers.

External communication is via HTTPS and so enjoys 128-bit SSL protection if you use Exchange Server 2003. The Xkey can accept X.509 certificates for Exchange Server authentication. These are stored in a tamper-proof area outside of the Xkey’s file system. The Xkey temporarily installs a kernel level keyboard driver that bypasses any keystroke logger.

Although the latest incarnation of OWA with Exchange Server 2003 is the most secure yet, security remains a potential issue with OWA, particularly with Exchange Server 2000. Xkey side-steps these problems by closing all browser windows and terminating the Exchange session, deleting temporary Internet files, the browser history and its cookies too.

The competition
OWA with Exchange Server 2003 offers pretty much the same feature set as Xkey but for free. Xkey’s biggest advantage over OWA is that OWA can’t be used offline. However, thanks to its integral database, Xkey lets you can access all your emails and appointments and compose new messages and so on without a live server connection, the Xkey sending the emails the next time it connects with the Exchange Server.

There’s a performance benefit too – once initially synchronised, further sync’ing only downloads new emails or appointments, which is relatively swift. Synchronisation occurs every time an Internet connection is detected, even if the device is in Offline mode. Unlike OWA, elements of the GUI (as well as your Inbox) are cached locally in its application server and don’t have to be downloaded every time you sync.


£240 might seem a lot to pay for a glorified 256MB USB memory key but the Xkey offers good value for money. It’s very easy to deploy as no additional software (not even Office) needs to be installed at either end. For end users, the Xkey makes it easy to work from any PC safely without having to lug around a laptop or worry about making network connections. For laptop users, it’s a useful standby in the event of PC loss, damage or theft. For others, this smart memory key is a relatively cheap and secure travel option.