Biometrics

1
Chapter 13

• Biometrics
• What you are

2
Handwritten signatures

• Requires careful examination
• Rarely examined closely
• Electronic examination has high fault rates
• Have to use signature tablet
• Detects velocity etc of signature

3
Biometrics

• Trade-off
• False acceptance rate
• Fraud (type 1)
• False rejection rate
• Insult (type 2)
• Must balance
• Often times simply used as deterrent in retail
• Or as supplement

4
Face recognition

• Oldest method of all
• Humans very unreliable in doing this with
  strangers
• Yet widely used in photo IDs
• Again often a simple deterrent
• Electronically
• Identity verification
• Face in crowd

5
Fingerprints

• Large player in biometric industry
• Accepted in our culture for identification
• Used widely in law enforcement for identification
• Matching against database time consuming
• Proper to use in sweeps
• DNA replacing to some degree

6
FingerPrints

• When doing sweeps even very small false
  positive rates bite you
• Fingerprint impressions are noisy
• Assumption that a method is infallible generates
  complacency in use
• Belief that is infallible produces extreme
  consequences when it does

7
Iris Codes

• Advantages
• Best error rates
• Limited genetic influence
• Very random
• Disadvantages
• Intrusive to obtain
• Possible impersonation attacks using pictures

8
Voice Recognition

• Problems
• Background noise
• Digital reproduction from previously recorded
• Imitation
• Forensic Phonology
• Matching voice to phone call

9
Others

• Face thermo grams
• Scent
• Hand geometry
• Gait
• DNA (spit in the device ?)

10
What goes wrong

• DNA high false positives, sloppy lab work
• Environmental conditions
• Age (in law enforcement)
• Print must be new
• Grannies finger in pickle jar
• Collusions
• Intentionally downgrade sample (handwritting)
• Combining biometrics to get lower error rate
• May increase false negatives
• Anomalies in the population
• Damaged fingerprints
• Missing hands
• Religious issues

11
Articles

• Case of false positive with fingerprints
• echelon carnivore
• Religious issues and biometric identification