Question

1. Which could boost the security of a single factor password-based authentication method without adding something the individual “has” or “is” authentication factors?

1. Requiring the use of very long and random passwords
2. Checking the registry information of a caller's cell phone against a registry
3. Requiring that a cell phone user submit a voice recognition sample
4. Performing callback verification to a previously registered cell phone

Answer 1

The answer is option (a), the use of long and random passwords.

A single factor authentication does not require a second factor (something that the person logging in "has" or "is"), over and above the original factor which mosty is a password or pin. Except (a), all the options require a sceond factor/comparison against something, whether that be b) checking registry information of a caller, c) checking against a voice sample or d) doing a callback verification. A long and random password makes unauthorized access difficult.