Abstract: Systems and methods for token authentication analyze token data over one or more read operations to compute a characteristic master signature for the token. This can be accomplished, for example by analyzing the token data statistically to compute a characteristic signature for the token. Similar techniques can be used to generate a subsequent signature that can be verified against the original characteristic signature to authenticate the token. For example, a signature can be generated on a per use basis and that signature verified against the characteristic signature to validate the token upon use.