+ Universal - no special hardware required
+ Revocable – can cancel and create new credential if compromised
+ Hard to verify who is presenting the credential
+ May not notice compromise immediately
+ Revocable – can cancel and reissue new credential if compromised
+ Quickly notice if lost or stolen
+ Hard to copy/mimic
+ Cannot be lost, forgotten, or stolen
+ Requires special hardware, so not universally applicable
+ User resistance. Some people may object to use of fingerprints; some culture groups may refuse face recognition, etc.
+ May create threat to privacy. For example, retina scans may reveal health conditions.
+ False rejection due to change in biometric characteristic (e.g., voice recognition may fail if have a cold).
+ Not revocable. If the biometric template is compromised, it cannot be re-issued (e.g., you cannot assign someone a new fingerprint).