One-class naïve Bayes with duration feature ranking for accurate user authentication using keystroke dynamics

Biometric-based approaches, including keystroke dynamics on keyboards, mice, and mobile devices, have incorporated machine learning algorithms to learn users’ typing behavior for authentication systems. Among the machine learning algorithms, one-class naïve Bayes (ONENB) has been shown to be effective when it is applied to anomaly tests; however, there have been few studies on applying the ONENB algorithm to keystroke dynamics-based authentication. We applied the ONENB algorithm to calculate the likelihood of attributes in keystroke dynamics data. Additionally, we propose the speed inspection in typing skills (SITS) algorithm designed from the observation that every person has a different typing speed on specific keys. These specific characteristics, also known as the keystroke’s index order, can be used as essential patterns for authentication systems to distinguish between a genuine user and imposter. To further evaluate the effectiveness of the SITS algorithm and examine the quality of each attribute type (e.g., dwell time and flight time), we investigated the influence of attribute types on the keystroke’s index order. From the experimental results of the proposed algorithms and their combination, we observed that the shortest/longest time attributes and separation of the attributes are useful for enhancing the performance of the proposed algorithms.