CS2 player aced his Master's thesis by building a biometric cheat-detection system

Christopher B. Didriksen, a student at the Norwegian University of Science and Technology, just finished a Master's thesis built entirely around one of Counter-Strike 2's most persistent problems: banned cheaters coming straight back on fresh accounts. He got an A.

Didriksen's system works by fingerprinting how individual players move their mouse and use their keyboard during CS2 matches, pulling data from competitive match demos. That fingerprint, he found, stays stable across maps, sessions, sensitivity changes — even across matches played months apart. In a dataset of over 1,000 players, mouse movement biometrics correctly identified the right player every time, though often by a narrow margin. Keyboard data alone hit 98% accuracy. Cross-referencing both signals pushes identification accuracy higher still. Didriksen says the system is fast enough to check every new match against all of CS2's monthly active players, and it already found smurf accounts that nobody had reported. His pitch to Valve: let this sit alongside VAC and Trust Factor and answer the one question they can't — is this the same human behind the account?

Smurf accounts — secondary accounts used by experienced or high-ranked players to stomp lower-ranked lobbies — are a long-standing headache in competitive shooters, and CS2 is no exception. Current anti-cheat systems like VAC focus on detecting cheat software rather than identifying the person running it, which means a hardware or account ban doesn't stop a determined cheater from simply buying a new copy and starting over. Biometric behavioral fingerprinting sidesteps the software detection problem entirely by targeting the human, not the tools.

Didriksen is upfront about the limitations: the system can't account for the possibility that a banned player genuinely reforms, and shared accounts would confuse it. Still, the r/CS2 community helped make the research possible — some Redditors who volunteered for the study even disclosed their own smurf accounts, data Didriksen called some of the most valuable he collected. He thanked the subreddit directly when posting his results, noting the thesis wouldn't have been possible without them.