1. A method for verifying an identity of a user comprising: prompting a user to speak a first dynamic phrase (FDP) comprising at least one dynamically-generated word, the dynamically-generated word generated based on data associated with the user; extracting at least one voice characteristic from a received FDP utterance and comparing the at least one voice characteristic with a voice profile; and determining whether to accept a speaker identity based on the comparison of the at least one voice characteristic with the voice profile.