A New Protocol to Evaluate the Resistance of Template Update Systems Against Zero-Effort Attacks

Since several years, there is a high interest in the cre-ation of template update mechanisms in biometrics. By automatically updating over time the biometric reference of an individual, these update systems aim at avoiding a performance decreases over time. However, update errors occur when impostor samples are included in the biomet-ric reference. In this paper, we are interested in analysing the behavior of template update against zero effort at-tacks depending on the difficulty of these attacks which is parametrized by the ratio of impostors samples included. We propose a protocol, which allows to evaluate an update mechanism under such kind of attacks by preserving an im-portant amount of genuine samples, even when the ratio of impostor samples is important. Then, we apply this proto-col on an existing template update system from the state of the art at various attack rates in order to assess its benefits. 1