A student of FIT BUT designed a device for signatures forging to be one step ahead of the forgers

All that is needed is to sign your name with a special pen with sensors that collect data on the way you write. The attached 3D printer then manages to create its forged copy. The forgery device, which can imitate the dynamic properties of handwriting, was designed by Jan Pawlus from FIT BUT in co-operation with police handwriting experts. In the future, it should help detect machine signature forgeries.

At the Faculty of Information Technology of BUT, experts are engaged in recognition of people on the basis of characteristic features - fingerprint, iris structure or face shape, i.e. biometric characteristics, and their possible falsifications. "One's signature is also very individual. Each of us writes at a different speed in various parts of the signature and applying different pressure. If someone tries to forge someone else's signature only by imitating its shape, the experts in handwriting can easily recognise such forgery under a microscope," said Jan Pawlus of FIT BUT, who designed a device for forging signatures as part of his thesis. "People feel that they always sign differently. However, this is expected and it is not even that important. When experts on handwriting compare signatures, they are more interested in the dynamic properties of the handwriting and the routine movements of the hand," described Pawlus, who co-operated with the police experts during his work.

First, the student designed a specialised mechanic pencil similar to a common pen, which contained switches for handwriting detection. The pencil is connected to sensors collecting data on the curve and the angle in which the pencil is held, as well as the speed of writing. "I have developed a program that can reconstruct the signature based on the data obtained. All one needs to do to forge the signature is to take a picture of the original signature and map the collected data on the picture. All the information is then sent to a 3D printer which will create the forged copy," added Pawlus.

Pawlus's aim is to acquaint experts on handwriting with new technologies used for forging signatures | Author: Jan Pawlus

In his thesis, Jan Pawlus attempts to show what new technologies can be used for forging signatures so as to take the wind out of the forgers' sails. "I have only designed a prototype that will need to be further elaborated because the outputs are not convincing. My design is not worth copying for the forgers. The next prototype of the pen should be equipped with better-quality sensors and pressure meter, because the pressure applied to paper is one of the important characteristics of handwriting. The use of a 3D printer, which is not the most suitable production tool, is also worth re-considering," explained Pawlus, who would like to further co-operate with BUT on the development of the device. "My model of the pen has sensors connected from the outside, but, ideally, they should be installed inside the pen. Therefore, people wouldn't know that they are writing with a pen that has been tampered with," he noted.

High-quality machine forgeries of signatures that can credibly imitate both the dynamic and plastic properties of the original handwriting will become a challenge for handwriting experts in the future. "We need to regularly inform experts about technologies like this that can be used to forge signatures so that they are able to look for new distinguishing characteristics of the copies that they have not identified so far," concluded the student.