A method for training a classifier for authenticating signatures hand-drawn on an electronic input element includes receiving a set of multiple signature properties of each of multiple signatures documented over a time range of a common user, each set of multiple signature properties is associated with a time period during which a respective signature was documented at the time range, wherein the plurality of signatures were hand-drawn and digitally recorded using an electronic input element; generating a signature authenticating classifier for authenticating additional signatures of the common user based on the set of multiple signature properties of each of the plurality of signatures, wherein a weight assigned to each the set of multiple signature properties or a portion thereof decreases overtime, the weight is used for the generation of the classifier; and providing the signature authenticating classifier for authenticating the additional signatures.