The poor old signature is running out of steam as a guarantee of identity in this digital era.
The shape of a signature alone is very easy to fake, given just limited amounts of practice. Those systems which still use signatures tend to monitor the dynamics of how the letters are formed just as much as the final image…and this requires cameras, touchscreens, accelerometers and who knows what else in terms of computing.
Today’s invention is a ballpoint pen which writes, as normal, on any old piece of paper but which whose output incorporates biometric information about the dynamics of the writer’s hand.
Think about writing with a tube of stripey toothpaste, except that the stripes are of different colours (or consist of dots and dashes with different mark/space frequencies). Scale this idea down a little and you have a pen which will output different ink composition, from millisecond to millisecond, dependent upon the direction of movement of the ball relative to the barrel. (Obviously, the pen would need to be held consistently -perhaps by moulding in fingerpads into the outside of the pen itself).
This could be detected (coarsely) using only a magifying glass and would reduce any doubt about the ownership of a signature or even of an author’s manuscript. In particular, a computer loaded with statistical directional characteristics of one’s writing could generate a phrase (in black and white text) for a signatory to copy and have analysed to confirm their claims.