Hey ... You're Not My User! Software Identifies Computer Users By Typing Style

The technology can be extended to other applications that involve a sufficiently complex interaction between humans and machines. Examples of such applications would include the identification of unauthorized drivers or pilots.

The system prototype was developed in the Data Mining Lab of the Technion’s Computer Science Faculty by students Ido Yariv and Mordechai Nisenson, under the supervision of Technion Professors Ran El-Yaniv and Ron Meir. The group’s findings were presented on September 25, 2003 at the European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML/PKDD) held in Cavtat, Croatia.

"This software is based upon a universal prediction algorithm," explains El-Yaniv. "It utilizes statistics gathered while a person types freely, and learns the specific behavior patterns that accurately identify the typist." He goes on to explain that time differential patterns between consecutive keystrokes can uniquely determine a user. In some cases, this can be accomplished after only a very few keystrokes.

The system’s innovation is the ability to identify the legal user as he/she types freely, a stark contrast to currently existing technologies that can only achieve equally high recognition rates if both the legal user and the intruder are asked to type the same long sentence (similar to standard passwords).

The system’s accuracy depends upon the length of its training. But even after a relatively short session consisting of several typed sentences, the system can distinguish the user from potential intruders with around 90 percent accuracy from a sentence as short as ‘What did you do today?’ After its initial training, the system continues monitoring the user and obtaining more keystroke sequences, allowing it to reach extremely high rates of recognition.

According to El-Yaniv, typing is a complex sequence of events. Many processes and factors make up this sequence, including language fluency, mental attributes, fine motor skills, hand size and finger length. As part of their ongoing research, the group will study the system’s reliability in the face of "noise" that can be introduced by many factors such as a finger injury. El-Yaniv believes that since it is the user’s behavior that is being measured (through the timing of keystrokes), there would still be enough information by which to make a very accurate identification.

The Technion-Israel Institute of Technology is Israel's leading science and technology university. It commands a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel's high-tech companies are alumni. Based in New York City, the American Technion Society is the leading American organization supporting higher education in Israel, with more than 20,000 supporters and 19 offices around the country.