DOI: 10.4018/IJT.2020070103 International Journal of Technoethics Volume 11 • Issue 2 • July-December 2020 Copyright © 2020, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. 34 The Keyboard Knows About You: Revealing User Characteristics via Keystroke Dynamics Ioannis Tsimperidis, Democritus University of Thrace, Greece https://orcid.org/0000-0003-0682-1750 Avi Arampatzis, Democritus University of Thrace, Greece https://orcid.org/0000-0003-2415-4592 ABSTRACT One of the causes of several problems on the internet, such as financial fraud, cyber-bullying, and seduction of minors, is the complete anonymity that a malicious user can maintain. Most methods that have been proposed to remove this anonymity are either intrusive, or violate privacy, or expensive. This paper proposes the recognition of certain characteristics of an unknown user through keystroke dynamics, which is the way a person is typing. The evaluation of the method consists of three stages: the acquisition of keystroke dynamics data from 118 volunteers during the daily use of their devices, the extraction and selection of keystroke dynamics features based on their information gain, and the testing of user characteristics recognition by training five well-known machine learning models. Experimental results show that it is possible to identify the gender, the age group, the handedness, and the educational level of an unknown user with high accuracy. KeYwoRDS Data Mining, Digital Forensics, Feature Selection, Information Gain, Keystroke Dynamics, User Characteristic Classification INTRoDUCTIoN Today there are more than 4 billion Internet users in the world who use online services in order to communicate, entertain, educate, work, etc. The way we communicate over the Internet with someone else differs radically from the way we do it in person. Most of the time we do not see the face of our interlocutor, nor his/her expressions, we do not hear his/her voice, nor the way its tone changes. The stimuli that used to give us information about who our interlocutor is and what his/ her intentions are, have ceased to exist. In addition, we have to consider that often a user is talking to someone completely unknown and that kids and teenagers participate in these conversations, especially in social networks. It is easily understood that these lurk many dangers, such as financial fraud, seduction of minors, anonymous threats, etc. In addition, it raises the question of how ethical it is for someone to take advantage of this particularity of communication and to conceal his/her identity from his/her interlocutor. According to the definition of “Technoethics” from the work of Alim and Khalid (2019), technology (apart from being part of social development) causes changes in lifestyle and as a result