1. A computerized method for generating a new signature of a user to prevent user impersonation, comprising a computer processor steps of, a. fetching a signal from a non-volatile memory of at least one portion of at least one previously generated user's signature; b. generating at least one challenge sequence based on the signal to create a new signature; c. presenting the generated challenge sequence to the user; d. collecting the user's challenge response to the generated challenge sequence; and, e. computing a quality factor which represents a degree of correlation between any portion of the user's challenge response and any portion of the generated challenge sequence; f. generating a new signature based on any portion of user's challenge response and any portion of the previously generated signature and any portion of collectable information from user's device memory; and, g. storing at least one of, the new signature, the quality factor, the trust factor and/or the transaction quality factor in a non-volatile memory or communicating it to a computer program.