Date: October 18, 2013 Homework due: Oct. 18 at 5:00pm
Challenge-response
Computer issues challenge, user presents response to verify secret information known or item possessed
Example operations: f(x) = x+1, x random; string (for users without computers); something based on time of day; computer sends E(x), you answer E(D(E(x))+1)
Note: password never sent on wire or network
Biometrics
Depend on physical characteristics
Examples: pattern of typing (remarkably effective), retinal scans, etc.
Location
Bind user to some location detection device (human, GPS)