The invention relates to a data processing device (100) enabling a user to input characters, the device comprising a touch-sensitive member (200) arranged to function as a virtual keyboard, said member including at least one touch sensor (160) for detecting touched zones on said member. The device further comprises key allocation means (110) for allocating at least two reference keys (220) of the virtual keyboard in response to said detection of the touched zones. The device comprises at least one pressure sensor (170) for sensing a finger (250) causing a force on the touch-sensitive member higher than other fingers when more than one finger touches said member. A recognition of a key stroke may be realized. The reference keys may be reallocated upon a user's request or detection of a predetermined condition. The invention also relates to a method of enabling a user to input characters.