Biometric Authentication Presenter: Yaoyu, Zhang Presenter: Yaoyu, Zhang

Preface  We can authenticate an identity in three ways: by something the user knows (such as a password or personal identification number), something the user has (a security token) or something the user is (a physical characteristic, such as a fingerprint, called a biometric).

Abstract  Introduction to biometric authentication  Some related concepts  Biometric Methods  Can biometric authentication be fooled  Some issues about Access Control

Biometric Authentication  Biometric Authentication  Authentication based on body measurements and motions  It is easy because you always bring your body with you  Biometric Systems  Enrollment  Later access attempts  Acceptance or rejection

Biometric Authentication System 1. Initial Enrollment 2. Subsequent Access User Lee Scanning Applicant Scanning Template Database Brown Lee Chun Hirota … 3. Match Index Decision Criterion (Close Enough?) Processing (Key Feature Extraction) A=01, B=101, C=001 User Lee Template ( ) User Access Data ( ) Processing (Key Feature Extraction) A=01, B=111, C=001

Biometric Authentication  Verification Versus Identification  Verification: Are applicants who they claim to be? (compare with single template)  Identification: Who is the applicant? (compare with all templates)  More difficult than verification because must compare to many templates  Watch list: is this person a member of a specific group (e.g., known terrorists)  Verification is good for replacing passwords in logins  Identification is good for door access and other situations where entering a name would be difficult

FAR  Precision  False acceptance rates (FARs): Percentage of unauthorized people allowed in  Person falsely accepted as member of a group  Person allowed through a door who should not be allowed through it  Very bad for security

FRR  Precision  False rejection rates (FRRs): Percentage of authorized people not recognized as being members of the group  Valid person denied door access or server login because not recognized  Can be reduced by allowing multiple access attempts  High FRRs will harm user acceptance because users are angered by being falsely forbidden

Biometric Authentication  Precision  Vendor claims for FARs and FRRs tend to be exaggerated because they often perform tests under ideal circumstances  For instance, having only small numbers of users in the database  For instance, by using perfect lighting, extremely clean readers, and other conditions rarely seen in the real world

Biometric Authentication  User Acceptance is Crucial  Strong user resistance can kill a system  Fingerprint recognition may have a criminal connotation  Some methods are difficult to use, such as iris recognition, which requires the eye to be lined up carefully.  These require a disciplined group

Biometric Authentication  Biometric Methods  Fingerprint recognition  Dominates the biometric market today  Based on a finger’s distinctive pattern of whorls, arches, and loops  Simple, inexpensive, well-proven  Weak security: can be defeated fairly easily with copies  Useful in modest-security areas

Biometric Authentication  Biometric Methods  Iris recognition  Pattern in colored part of eye  Very low FARs  High FRR if eye is not lined up correctly can harm acceptance  Reader is a camera—does not send light into the eye!

Biometric Authentication  Biometric Methods  Face recognition  Can be put in public places for surreptitious identification (identification without citizen or employee knowledge). More later.  Hand geometry: shape of hand  Voice recognition  High error rates  Easy to fool with recordings

Biometric Authentication  Biometric Methods  Keystroke recognition  Rhythm of typing  Normally restricted to passwords  Ongoing during session could allow continuous authentication  Signature recognition  Pattern and writing dynamics  Biometric Standards  Almost no standardization  Worst for user data (fingerprint feature databases)  Get locked into single vendors

Biometric Authentication  Can Biometrics be Fooled?  Airport face recognition  Identification of people passing in front of a camera  False rejection rate: rate of not identifying person as being in the database  Fail to recognize a criminal, terrorist, etc.  FRRs are bad  4-week trial of face recognition at Palm Beach International Airport  Only 250 volunteers in the user database (unrealistically small)  Volunteers were scanned 958 times during the trial  Only recognized 455 times! (47%)  53% FRR

Biometric Authentication  Can Biometrics be Fooled?  Airport face recognition  Recognition rate fell if wore glasses (especially tinted), looked away  Would be worse with larger database  Would be worse if photographs were not good  DOD (Department of Defense )Tests indicate poor acceptance rates when subjects were not attempting to evade  270-person test  Face recognition recognized person only 51 percent of time  Even iris recognition only recognized the person 94 percent of the time!

Biometrics Authentication  Can Biometrics be Fooled?  Other research has shown that evasion is often successful for some methods  German c’t magazine fooled most face and fingerprint recognition systems  Prof. Matsumoto fooled fingerprint scanners 80 percent of the time with a gelatin finger created from a latent (invisible to the naked eye) print on a drinking glass

Access Control  Access Control  Access control is the policy-driven limitation of access to systems, data, and dialogs  Goals  Prevent attackers from gaining access, stopping them if they do  Provide appropriate limitations on the access rights of authorized users

Access Control  First Steps  Enumeration of Resources  Sensitivity of Each Resource  Next, who Should Have Access?  Can be made individual by individual  More efficient to define by roles (logged-in users, system administrators, project team members, etc.)

Access Control  Policy-Based Access Control and Protection  Have a specific access control policy and an access protection policy for each resource  For example, for a file on a server, for instance, limit authorizations to a small group, harden the server against attack, use a firewall to thwart external attackers, etc.  Focuses attention on each resource  Guides the selection and configuration of firewalls and other protections  Guides the periodic auditing and testing of protection plans