WEP-WAPWEP-WAP

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GoalsGoals

Biometric protocols suitable for a wireless networked environment

Secure system/network access via biometric authentication

Secure wireless transmission of biometric data

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Why Wireless Biometrics?Why Wireless Biometrics?

Combination of two rapidly growing technologies1. Biometric systems for verification and

identification• Homeland Security

2. Wireless systems for mobility• Over 1 trillion wireless phone min. in US,

2004

Common advantage is convenience

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Human authenticationHuman authentication

Types of human authentication– What you know (secret)

• Password, PIN, mother’s maiden name

– What you have (token)• ATM card, smart card

– What you are (biometric)• Stable: fingerprint, face, iris• Alterable: voice, keystroke

– Where you are (authorization?)• Wireless

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Biometric AdvantagesBiometric Advantages

Convenience– Can’t be lost (in general)– Can’t be forgotten

Can’t be loaned Mostly unique (matching may not be) Perceived strong non-repudiation Does not change significantly (in general)

(Ident.) Both verification and identification

applications

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Biometric Authentication SystemBiometric Authentication System

Source: Podio, NIST

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Wireless Biometric System SecurityWireless Biometric System Security

Security issues– Biometric authentication to ensure secure

access to the system/network• In other words, wireless system access security

– Wireless message authentication to ensure secure transmission of biometric data• In other words, personal information security and

privacy across the wireless network

– Physical security• Devices, computers, transmitters/receivers, etc.

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Biometric Authentication ThreatsBiometric Authentication Threats

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Biometric CryptographyBiometric Cryptography

Use of biometric data for encryption & decryption

“fuzzy” commitment, vault – Ari Juels, RSA Labs

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Biometric Cryptography (example)Biometric Cryptography (example)

Template(key)

Password(hashed) E(h(Pwd))

Enroll(Encrypt)

Verify(Decrypt)

Template(key)

compare

00000 1111101010 10101 01010 01010

11010 11101

10000 10111

HammingDistance = 2

WithinThreshold?

“stored”

“live”

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Biometrics StandardsBiometrics Standards Common Biometric Exchange File Format (CBEFF) ANSI-NIST-ITL-2000

– Data exchange & quality– Criminal identification

American Association for Motor Vehicle Administration (AAMVA) DL/ID 2000

FBI – Wavelet Scalar Quantization (WSQ) – fingerprint image (de)compression– Electronic Fingerprint Transmission Standard (EFTS)

Intel Common Data Security Architecture (CDSA) ANSI X9.84 – Biometric data security (life cycle)

– Originally developed for financial industry; uses CBEFF APIs

– Open: BioAPI, Java Card Biometric API; uses CBEFF– Proprietary: BAPI …what is Microsoft planning?

XCBF– XML Common Biometric Format from OASIS; uses CBEFF– Mechanisms for secure transmission, storage, integrity, & privacy of biometrics

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Biometric StandardsBiometric Standards

Recently from NIST…– Biometric Data Specification for Personal

Identity Verification (PIV)• January 24, 2005 (Draft)• New standards governing interoperable use of

identity credentials to allow physical and logical access to federal government locations and systems– Technical and formatting requirements for biometric

credentials– Restricts values and practices for fingerprints and

facial images– Geared toward FBI background checks and formatting

data for a PIV card– CBEFF and BioAPI compliant

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Wireless AdvantagesWireless Advantages

Mobility Flexibility

– Easier to relocate and configure– More scalable

Cost– No cost due to physical barriers, private property.

Productivity– More opportunity to connect

Aesthetics– No clutter from wires

Robustness– Less physical infrastructure to damage and repair

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Wireless DisadvantagesWireless Disadvantages

Lower channel capacity– Limited spectrum available– Power restrictions– Noise levels

Noise and interference Frequency allocation– U.S. – FCC

Greater security concern– Information traveling in free space

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Wireless ProtocolsWireless Protocols Network domains

– Broadband• IEEE 802.16, Worldwide Interoperability for Microwave Access (WiMAX) –

framework, not single system or class of service– Cellular networks

• Global System for Mobile communication (GSM)• Universal Mobile Telecommunications System (UMTS =WCDMA)

– Cordless systems• Time Division Multiple Access (TDMA)• Time Division Duplex (TDD)

– Mobile Internet Protocol (Mobile IP) – Wireless Local Area Network (WLAN)

• IEEE 802.11 (Wi-Fi) a,b,g (n … not yet ratified)– Wireless Personal Area Network (WPAN)

• IrDA, Bluetooth, ultra wideband, wireless USB– Home Automation (narrow band)

• Infineon, ZigBee, Z-Wave

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Wireless Protocol ComparisonWireless Protocol Comparison

Source: PC Magazine, March 22, 2004

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Security and ProtocolsSecurity and Protocols Security domains

– Application security• Wireless Application Protocol (WAP)

– Uses Wireless Transport Layer Security (WTLS)• Current Class 2 devices based on IETF SSL/TLS• Future Class 3 devices will use a WAP Identity Module (WIM)

• Web services– Simple Object Access Protocol (SOAP) – toolkits available for Java & .NET

• Operating system security (Java run-time, Palm OS, Microsoft Windows CE)– Device security (PINs, pass-phrases, biometrics)– Security of wireless protocols

• IEEE 802.11 (Wi-Fi)– Wireless Encryption Protocol (WEP)… weak and flawed– Wi-Fi Protected Access (WPA). Uses Temporal Key Integrity Protocol (TKIP)

• IEEE 802.11i – Wireless Security spec. (WPA, AES, FIPS 140-2 compliant)– Authentication security

• Remote Authentication Dial In User Service (RADIUS)• Kerberos• SSL

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Network EncryptionNetwork Encryption

Secure Shell (SSH)– Application Layer– Secure remote connection replacement for telnet, rlogin,

rsh Secure Socket Layer (SSL)

– Transport Layer Security (TLS)– Uses TCP & has specific port numbers– Main use is HTTPS (port 443)

Internet Protocol Security (IPSec)– Network Layer– Includes a key management protocol– Included in IPv6

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Avenues of AttackAvenues of Attack

Capture Device

Local ComputerLAN- connected Computer

LAN

WAN

Remote Computer

= wireless

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Wireless Security IssuesWireless Security Issues Denial of Service (DoS)

– Jamming…Use Spread Spectrum (DSSS, FHSS) technology– As a device battery attack, i.e., more processing = more battery usage

Eavesdropping– Signal is in the open air (war dialing)

Theft or loss of device– Due to size, portability, and utility

Dependency on public-shared infrastructure– What security is in place?

Masquerading– Rogue clients pretend to be legitimate endpoint– Rogue access points trick clients to logging in

Malware– Worms (Cabir) and Viruses (Timfonica, Phage) on wireless devices– Use Antivirus software

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Wireless Security ParadoxWireless Security Paradox

We use wireless devices for convenience

Security measures often decrease convenience and performance

Result: Security features are often disabled or given lower priority

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System Design ConsiderationsSystem Design Considerations Verification

– Are you who you claim to be (or are supposed to be)?– 1:1 matching– Usually consensual– Typically smaller template databases– Authorization (computer, network, building)

Identification– Who are you?– 1:n matching– Often no explicit consent or awareness– Typically larger template databases– Surveillance (homeland and border security), forensics, criminal

investigation (AFIS) Why not both?

– i.e. You are not who you say you are, so who are you?

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Future ResearchFuture Research

Pattern for “fuzzy” matching?– Biometrics, digital watermarks, IDS, search

engines Biometric cryptography– Biometric key generation

• Fuzzy matching methodologies• Embedding biometric keys within wireless protocols

– X.509 certificates– Protocol payload area– Protocol header (authentication) area

• Use coefficients? (polynomial, elliptic curve)