Template renewal in helper data systems

摘要

The invention provides a method for authenticating a physical object (OBJ) using a first helper data (W1) and a first control value (V1) associated with a reference object. The method comprises a step to generate a first property set (S1) using a noise compensating mapping (NCM) on information derived from the first helper data (W1) and a metric data (Y) associated with the physical object, and a step to establish a sufficient match between the physical object and the reference object using the first property set (S1) and the first control value (V1). The method further comprises a step to generate an update data (WUPD) for updating the first helper data (W1) using the first helper data (W1), the first property set (S1) and the metric data (Y). Also provided is a client terminal configured to carry out the method.