Introduction to Biometrics

Dr. Pushkin Kachroo

New Field

• Face recognition from computer vision

• Speaker recognition from signal processing

• Finger prints from forensics and pattern recognition

Organization-1

• Basics: – Core biometric concepts– General authentication protocols for

• Verification• Identification• Screening

– Most common• Finger, face, voice, iris, hand, signature, etc.• Skin reflectance, gait, etc.

Organization-2

• Performance and Selection– Fundamental measurable aspects affecting

system accuracy– Realistic Error Rates

• System Issues– Overall design– Threat Models– Databases, APIs etc.

Organization-3

• Mathematical Analyses – Analyses for Evaluation and Selection of

Biometric System– Stochastic Methods– Optimzation (Error minimization)

Authentication

• Standard Methods:– ID cards, passports etc.– Problems:

• Misplaced, get lost, forged• Automating identification

Biometrics

• Biometric Identification– Verification: (Easier)– Identification: (More difficult with large

databases)

Applications

• Boarding an Aircraft

• Performing a financial transaction

• Picking up a child from daycare

• Office and home security

Distinct Personal Characteristics

• Physiological – Static Measurement– Fingerprint, hand geometry etc.

• Behavioral– Dynamic (temporal measurement)– Signature, gait, etc.

Person Authentication

• Three Traditional Modes– Possessions: keys, smart cards, passport

etc.– Knowledge: Passwords, user ID, mother’s

maiden name etc.– Biometrics: Physiological and Behavioral

Two Authentication Methods

• Verification: unique identifier which singles out a particular person (e.g. some I.D.) or person’s biometric.

• Identification: Compare with an entire database.

Desired Biometric Attributes

• Universality: Each person should have it

• Uniqueness: Each person different

• Permanence: Invariant over time

• Collectability: Sensors etc.

• Acceptability: Legally, socially etc.

Biometric Identifiers-1

• Common:– Physiological:

• Face, fingerprint, hand geometry, Iris

– Behavioral:• Signature• Voice

Biometric Identifiers-2

• Used less (or emerging):– Physiological:

• DNA, Ear Shape, Odor,Retina, Skin Reflectance, Thermogram

– Behavioral:• Gait, keystroke, lip motion

Biometric Subsystems

• Biometric Readers (sensors)

• Feature Extractors

• Feature Matchers

Authentication Systems

• For Enrollment

• For Authentication

System Performance & Design Issues-1

• System Accuracy– False Accept Rate (FAR)– False Reject Rate (FRR)

• Computation Speed– Scalability from small populations to large

• Exception Handling:– Failure to use (FTU), Failure to Enroll (FTE),

Failure to Acquire (FTA), etc.

System Performance & Design Issues-2

• System Cost

• Security

• Privacy

• Quantitative and qualitative parameters

Biometric Identification

• Reader, extractor, matcher (search in a database)– Positive Identification– Negative Identification

Biometric Verification

• Reader + I.D., extractor, Matching (with single)– Centralized databases– Distributed (e.g. smartcard stores the

biometric features of the person)

Biometric Enrollment

• Positive Enrollment– Of people who match certain criteria for

eligibility

• Negative– For non-eligibility

Biomeric System Security

• System Analyses

• Weakest point of failure

• Point failure verses dynamic