A system for graded authentication comprising user data obtained from {HEAD ~ a user} during at least one previously successful authentication attempt, past circumstantial data associated with the at least one previously successful authentication attempt and associated with enrollment data for the user, and a trust engine which generates a level of trust associated with a current authentication attempt based on the comparison of current circumstantial data associated with the current authentication attempt with {TAIL ~ the past circumstantial data} associated with the at least one previously successful authentication attempt 
A system for graded authentication comprising user data obtained from { HEAD ~ a user } during at least one previously successful authentication attempt , past circumstantial data associated with the at least one previously successful authentication attempt and associated with enrollment data for the user , and a trust engine which generates a level of trust associated with a current authentication attempt based on the comparison of current circumstantial data associated with the current authentication attempt with { TAIL ~ the past circumstantial data } associated with the at least one previously successful authentication attempt
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH