If there’s one major weakness of devices like the iPad and touchscreen-only mobile phones, it’s their onscreen keyboards. This is evidenced by the selection of portable keyboards available, such as the Jorno Bluetooth and Thanko folding keyboards. Citta Consulting is taking a different approach to portability to with its Kee4 Keyboard – a device that has just four keys and can be operated with one hand using a "composite keystroke" system.

The Kee4 is Bluetooth keyboard worn on one hand with the thumb inserted into a pouch to hold it in place. This allows the four fingers to rest on each of the device’s four keys so the user doesn’t have to move their fingers from key to key. If you’ve got a light touch you might be able to get away with using it freehanded, but resting it on a solid surface, such as the side of your body or an armrest, is recommended to stop the keyboard moving when the keys are pressed.

With only four keys and slightly more than four letters in the alphabet – not to mention numbers, upper and lowercase characters, symbols, foreign language characters and function controls – the unit relies on patented technology that uses a combination of keys, called composite keystrokes, to generate a full range of characters.

The device uses two types of composite keystrokes. The first, called a rocking composite keystroke, involves a rocking motion where the key that is pressed second is the first to be released. A rolling composite keystroke, on the other hand, (well, actually the same hand), involves a rolling motion where the first key that is pressed is the first to be released – kind of like drumming your fingers. The only exceptions are A, E, space and CTRL, which are generated with a single keystroke.

Obviously, such a system will take a bit of getting used to, but the demo video below proves it’s far from impossible. Citta Consulting has patented the device and is currently seeking investors to bring the Kee4 Keyboard to market. So if you’re interested in one day getting your hands on – or rather, hand in – the device, drop by the Kee4 website where there’s also a downloadable Kee4 Keyboard simulator to let you get your head around the composite keystrokes.