Affiliation: | a School of Social Science, Queensland University of Technology, Beams Rd., Carseldine, 4034, Qld., Australia b Centre for Applied Psychology, University of Canberra, Canberra, ACT, Australia c Department of Mathematics and Statistics, University of Saskatchewan, Saskatoon, ASAK, Canada, S7N OWO d The TRUST Project, RSISE, Australian National University, 0200, ACT, Australia |
Abstract: | The performance of Napier et al.'s typist verification algorithm (Keyboard user verification: toward an accurate, efficient, and ecologically valid algorithm, International Journal of Human-Computer Studies 43 (1995) 213-222) was assessed in a text-dependent setting. Twenty-nine subjects typed a 17 character password 50 times. False acceptance and false rejection rates were then calculated as the number of repetitions of the password included in the reference profile was increased from 6 to 20 and the number of digraphs from the password included in the verification process was increased from 2 to 16. The performance of the system (12% total error rate) was found to be comparable with the best results reported in other studies using text-dependent algorithms, and substantially better than that reported in studies using a text-independent paradigm with passwords of this length. The relationship between password length and reference profile size was found to conform to an exponential decay function, which accounted for 92% of the variability in verification error rates. |