Kostakos, VassilisRodrigues, Mário Amilcar Freitas2013-03-052013-03-0520092010http://hdl.handle.net/10400.13/348This project describes an authentication technique that is shoulder-surfing resistant. Shoulder surfing is an attack in which an attacker can get access to private information by observing the user’s interaction with a terminal, or by using recording tools to record the user interaction and study the obtained data, with the objective of obtaining unauthorized access to a target user’s personal information. The technique described here relies on gestural analysis coupled with a secondary channel of authentication that uses button pressing. The thesis presents and evaluates multiple alternative algorithms for gesture analysis, and furthermore assesses the effectiveness of the technique.engShoulder-surfingPeeping attackSecurityUsabilityAuthenticationCognometricsBiometricsMemometricsToken authenticatorsMulti-factor authentication.Centro de Ciências Exatas e da Engenhariamaster thesis