3 What is …Automatic recognition of a person using distinguishing traitsMeasurable: quantifying traitsRobustness: extent to which trait changes over timeDistinctiveness: measure of variations among patterns over a populationany automatically measurable, robust and distinctive physical characteristic or personal trait that can be used to identify an individual or verify the claimed identity of an individual.Biometric technologies may seem exotic, but their use is becoming increasingly common, and in 2001 MIT Technology Review named biometrics as one of the “top ten emerging technologies that will change the world.”Measurable means that the characteristic or trait can be easily presented to a sensor, located by it, and converted into a quantifiable, digital format. This measurability allows for matching to occur in a matter of seconds and makes it an automated process.The robustness of a biometric refers to the extent to which the characteristic or trait is subject to significant changes over time. These changes can occur as a result of age, injury, illness, occupational use, or chemical exposure. A highly robust biometric does not change significantly over time while a less robust biometric will change.Distinctiveness is a measure of the variations or differences in the biometric pattern among the general population. The higher the degree of distinctiveness, the more individual is the identifier. A low degree of distinctiveness indicates a biometric pattern found frequently in the general population. The iris and the retina have higher degrees of distinctiveness than hand or finger geometry.
4 Biometrics as Authentication… Something you are – BiometricIncreasing level of securityIncreasing convenienceSomething you know – PIN, passwordRelating Biometric to authentication. order of least secure and least convenient to most secure and most convenient.Something you have – card, token
5 Definition (contd.) Identification Verification Who is Who? “one-to-many” search (1:N)Used in identifying criminalsVerificationIs this Him/Her?“one-to-one” search (1:1)Used for physical or computer accessBiometrics are used for human recognition which consists of identification and verification.With identification, the biometric system asks and attempts to answer the question, “Who is Who?” In an identification application, the biometric device reads a sample and compares that sample against every record or template in the database. This type of comparison is called a “one-to-many” search (1:N). Identification applications are common when the goal is to identify criminals and terrorists.Verification occurs when the biometric system asks and attempts to answer the question, “Is this Him?” after the user claims to be X. In a verification application, the biometric system requires input from the user, at which time the user claims his identity via a password, token, or user name. This user input points the system to a template in the database. The system also requires a biometric sample from the user. It then compares the sample to or against the user-defined template. This is called a “one-to-one” search (1:1). The system will either find or fail to find a match between the two. Verification is commonly used for physical or computer access.
6 Biometric Technologies… FingerprintFingerprint pattern read & matched electronicallyIris RecognitionMeasurement of the Iris pattern of the eyeFacial RecognitionRecording spatial geometry of distinguishing featuresSpeaker/Voice RecognitionVoice or speaker recognition uses vocal characteristics for identificationFINGERPRINT: The biometric device involves users placing their finger on a platen for the print to be electronically read. The minutiae are then extracted by the vendor’s algorithm, which also makes a fingerprint pattern analysis.IRIS SCAN: Measures the iris pattern in the colored part of the eye. Iris patterns are formed randomly. As a result, the iris patterns in a person’s left and right eyes differ.FACIAL RECOGNITION: records the spatial geometry of distinguishing features of the face. Different vendors use different methods of facial recognition, however, all focus on measures of key features of the face. Because a person’s face can be captured by a camera from some distance away, facial recognition has a clandestine or covert capability.Speaker / Voice Recognition: Voice or speaker recognition uses vocal characteristics to identify individuals using a pass-phrase.
7 Facial Recognition Based on ability to recognize faces Nodal points 80 nodal points on the faceE.g.: Distance between eyes, width of nose, Cheekbones, Chin etc“Face-Print” – code of the faceNumerical CodeString of numbersFacial recognition software is based on the ability to first recognize faces, which is a technological feat in itself, and then measure the various features of each face.If you look in the mirror, you can see that your face has certain distinguishable landmarks. These are the peaks and valleys that make up the different facial features. These landmarks are known as nodal points. There are about 80 nodal points on a human face.Distance between eyesWidth of noseDepth of eye socketsCheekbonesJaw lineChinThese nodal points are measured to create a numerical code, a string of numbers, that represents the face in a database. This code is called a faceprint. Only 14 to 22 nodal points are needed for a lot of “face recognition software” to complete the recognition process.
8 Facial Recognition (contd.) Algorithm1) Capture Image2) Find Face on the image3) Extract Features (to generate template)4) Compare Templates5) Declare MatchesShow Example
9 Fingerprint Formation of a unique signature Combination of Environmental and Genetic Factors : Position of foetus, density of amniotic fluid, DNA’s impact on each ridgeThe lowest mis-identification rate after Iris recognitionThree main methods of capturing finger print :Thermal ImagingCapacitance ScannerOptical Reader
10 Thermal Imaging Sensor The sensor uses the heat patternsof the finger to create slices of aperson's fingerprintEach slice is then lined up usingcentering techniques
11 Capacitance and Optical Capacitance Sensing :The plates act as capacitorsFinger acts as third plateCapacitance under ridge higherCapacitance under valley lowerOptical Sensing : Uses Charged Coupled Devices (CCD). An Array ofphotosites which allow a current to flow through whenhit by photons. Darker areas are valleys and lighterareas are ridges.Capacitance will be higher under ridge than valley
12 Analysis of the Prints Typica : Minutiae Placement of ridges and valleys2) BifurcationsSplitting of lines into two andtheir recombining
13 Iris Recognition Background Identifying persons without physical contactUsed by the U.S. government, correctional facilities, nuclear utilities, banks, etc.The iris is the externally visible, colorful, donut-shaped organ surrounding the pupil of the eye.
14 Iris Recognition cont’d…(2) Uniqueness of the IrisThe iris is unique because of the morphogenesis of that organ.Stability of the IrisAn iris is not normally contaminated with foreign material (eyeglasses or contact lenses.)It is not subject to deleterious effects of aging. The features of the iris remain stable and fixed from about one year of age until death.
16 Iris Recognition cont’d…(4) Recognition SpeedDetermined by the speed of the processor and size of the database (normally less than two seconds).Sunglasses and colored contact lenses pose no impediment to recognition.Biggest AdvantagesAccuracy with an order of magnitude greater than other biometric systems.
17 Voice RecognitionAutomated process of identifying a specific individual's voiceSound signal is digitizedResult is a simple yes/no decisionDeployed in such areas as banking, account access, home PC and network access
18 Voice Recognition (cont…) AdvantagesEasy to use and require no special trainingNo need to periodically manage/change passwordsRelatively inexpensive compared to other biometrics