Acoustical keystroke analysis for user identification and authentication

This article describes a new algorithm of calibrated user authentication using acoustical monitoring of keyboard when typing the pre-defined word. The HMM (Hidden Markov Models) with MFCC (Mel-frequency cepstral coefficients) features were used in the setup. In authentication task a low EER (Equal Error Rate) was achieved between 9.4% and 14.8% using a calibration setup and 3 sessions training. For identification part the accuracy of 99.33% was achieved, when testing 25% of realizations (randomly selected from 100 recordings) identifying between 50 users/models. Calibration was done using one user recording to calibrate the microphone and keyboard table setup when enrolling his model. Genuine and impostor tests were realized for 50 volunteers typing 100 words each in 4 sessions.