1. Security and Privacy Issues in E-Passports
-Ari Juels, David Molnar, and David Wagner
Presented By: Vipul Gupta

2. A YouTube Video Link: http://www.youtube.com/watch?v=bZNfqztFlZU
4/27/2019

3. Outline Introduction Background Information Related Works
Security and Privacy Threats
E-Passport threats
Cryptography in E-Passports
Strengthening Today’s E-Passports
Future Issues in E-passports
Conclusions
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4. Introduction E-Passports (Biometric Passports) Need:
A new generation of Identity Cards
Combined paper and electronic document (uses integrated circuit chip)
Use the Radio Frequency Identification and Biometric Authentication Technologies
Need:
Reduce Fraud
Identity Check
Enhance Security
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5. US-VISIT Program Initiative of the Department of Homeland Security
Mandated adoption of Biometrically enabled passports by October 2006 under Visa Waiver Program (VWP)
VWP allows citizens of some countries to travel to the US for up to 90 days without obtaining the visa
The passports issued are based on ICAO guidelines
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6. International Civil Aviation Organization (ICAO)
Run by the United Nations
Responsible for setting international passport standards
Require incorporating RFID chips into passports
Microchips can store and transmit data wirelessly
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7. E-Passports
E-Passports will contain digitized photographs of their bearers
US-VISIT requires two fingerprint images in addition to the headshot
Malaysia has been issuing e-passports since 1998
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8. RFID Radio Frequency Identification
Communicates wirelessly with a reading device, using a “tag” also called as transponder
For E-Passports, ISO standard requires a radio frequency of MHz
Types of tags: Active and Passive
E-passports use passive tags, i.e. they do not have an onboard source of power - derive power indirectly from the interrogating signal of the reader
Tag read range is 10 cm
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9. RFID
The RFIDs used for E-passports are different from the ones used for Supply Chain Management
Tags used for SCM are simple, cheap and do not support cryptography; operate at 915 MHz; intended read range is 5 meters
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10. Biometrics
Verification of human identity through the measurement of biological characteristics
Mechanism through which human beings authenticate each other
For e-passport deployment biometrics preferred are:
Face Recognition
Fingerprints
Irises
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11. Biometrics
Process – An authenticated user “enrolls” by presenting an initial, high quality biometric image to the sensor
This information is stored as a template
In order to prove the identity during authentication, the user again presents the biometric to the sensor
Verification done by comparing with the template
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12. Related Works
Pattinson outlines privacy issues for e-passports that may be readable by anyone
Does not consider biometric data leakage
Jacob highlights the need for Basic Access Control and investigates issues
Smart Card Research Group (at IBM) demonstrated an application that performs basic access control and active access control in under 2 seconds
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13. Security and Privacy Threats
Clandestine Scanning
The ICAO guidelines do not mandate authenticated or encrypted communication between passports and readers
An unprotected passport chip is susceptible to clandestine scanning up to a few feet leading to leakage of personal information
Clandestine Tracking
The ISO standard stipulates the emission of a chip ID on protocol initiation
Unauthorized parties may use this to track a passport holder (provided the chip ID is unique for passport)
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14. Security and Privacy Threats
Skimming and Cloning
ICAO regulations mandate using digital signatures on e- passport data which can verify that data came from the correct passport issuing authority
However, digital signatures do not bind data to a particular passport or chip… Problem !!
Cryptographic Weaknesses
ICAO provides an optional mechanism for authenticating and encrypting passport-to-reader communications
Once the reader knows the key, there is no mechanism to revoke it
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15. Security and Privacy Threats
Eavesdropping
Faraday cage in e-passports – metallic material in the cover or holder that prevents the penetration of RFID signals
Do not protect from eavesdropping on legitimate passport to reader communication (as in airports)
Biometric Data-Leakage
E-passports to contain biometric images
Preventing this biometric information from leakage is important
Automated environments are not strictly controlled
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16. E-Passport Threats Data Leakage Threats Identity Thefts:
E-passports vulnerable to skimming
RFID readers can be installed in doorways; tags can be read from anyone passing through the doorways
Can be setup at a number of places like building entrances, shops, concerts, sporting events, etc.
Sensitive information contained in an e-passport can thus be compromised
Identity Thefts:
a photograph, name, birthday, (and additionally a SSN) may serve as ingredients to creating a new identity
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17. E-Passport Threats Tracking and Hotlisting:
static identifier allows for tracking the movements of RFID device
Hotlisting - explicit targeting of specific individuals
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18. E-Passport Threats Biometric Threat Automation leads to: Spilling:
Relaxation of Human Oversight
Spoofing of Biometric Authentication System
Spilling:
Compromise of data in one system, may affect the integrity of another unrelated system
Special qualities of passport pictures:
Image Quality: higher than what an attacker can obtain
Disclosure may enable forgery: Holding up a photo can spoof face recognition systems
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19. Cryptography in E-Passports
ICAO Specifies one mandatory use of cryptographic feature for e-passports
Passive Authentication:
data on an e-passport must be signed by the issuing nation using RSA, DSA (Digital Signature Algorithm) and ECDSA (Elliptic Curve DSA)
It demonstrates only that the data is authentic
It does not demonstrate that the container for data (e- passport) is authentic
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20. ICAO Specifications
Optional cryptographic features for improved security:
Basic Access Control and Secure Messaging
Stores a secret pair of keys on the chip (Kenc, Kmac)
When a reader attempts to scan passport, it engages in a challenge response protocol that proves the knowledge of keys and derives a session key
To ensure that tag data is read only by authorized RFID readers
If authentication is successful, passport releases data
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21. Basic Access Control
Keys are derived from optically scannable data printed on the passport -
A passport number (a nine number value)
Date of Birth
Date of Expiration of Passport
Three check digits, one for each of the above values
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22. ISO 11770-2 Key Establishment Mechanism 6 (Used by E-Passports)
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23. Drawbacks of Basic Access Control
Entropy of the keys is small (at most 56 bits)
Key length is slightly shorter for general population
Birth date yields about 14 bits of entropy
Expiration (max. 10 years) yields 11
US Passport numbers have at most 27 bits of entropy
Hence BAC keys have at most 52 bits of entropy
Single fixed key is used throughout the lifetime of the e-passport
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24. Active Authentication
While BAC is a confidentiality feature, Active Authentication is anti-cloning feature
Relies on Public Key Cryptography
E-Passport proves the possession of a private key
Corresponding public key is stored as part of signed data on the passport
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25. Active Authentication
Passport receives an 8-byte
challenge from the reader
Signs it using its private
key (SK) and returns result
Signature can be verified with
Passport’s public key
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26. Drawbacks of Active Authentication
Certificate required for verifying active authentication has enough information to derive key for BAC, hence it must be kept secret
Does not protect against Tracking and Hotlisting attacks even if BAC is in use
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27. Cryptographic Measures in Planned Deployments
Federal Register notice gives three reasons for not using Basic Access Control:
The data stored in the chip are identical to those printed in the passport
Encrypted data would slow entry processing time
Encryption would impose more difficult technical coordination requirements among nations implementing the e-passport system
E-passports will carry Faraday cages and readers will be shielded to prevent eavesdropping
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28. Federal Reasoning - flaws
Reason 3 is flawed - data required to derive keys for Basic Access Control is on the data page, no coordination amongst nations is required
Faraday cages cannot protect against unauthorized eavesdropping
Without BAC any ISO compliant reader can easily read data from the e-passport
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29. Strengthening Today’s E-passports
Faraday Cages
Simplest measure against unauthorized reading
Materials like aluminum fiber (opaque to RF signals) used to create a Faraday cage
Don’t prevent eavesdropping on legit reading
Larger secrets for BAC
52 bit entropy not enough
Add 128 bit secret (unique to each passport) to the key derivation algorithm
This secret could form a larger passport number or a separate field on the e-passport
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30. Strengthening Today’s E-passports
Private Collision Avoidance
ISO uses UID as part of its collision avoidance protocol
Countermeasure – pick a new random ID on every tag read
Beyond optically readable keys
Create a keying mechanism that limits a reader’s power to reuse secret keys
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31. Future Issues in E-passports
Visas and writable e-passports
Keeping visa information on the same chip (as different RFID may interfere with each other) – writing data to the e-passport after it has been issued
Function creep
Identification standardization may cause passports to become authenticators for consumer payments or mass transit passes
Age checking at a bar may yield other personal information like date and place of birth, passport number, etc.
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32. Current Deployment Status of E-Passports
In the European Union, while countries had been obliged to implement machine readable facial images since , they have to implement machine readable fingerprints by
Serbia (July 7, 2008), Philippines (mid-2009), Croatia (July 1,2009), Taiwan (since )
India (September 2009 – for regular citizens), Iran (early – for regular citizens)
Canada (2011 – for regular citizens)
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33. Conclusions
Unauthorized reading of e-passport data is a security risk as well as privacy risk
Faraday Cages and BAC should be used to prevent remote reading of e-passport data
Today’s e-passports are just a first wave of next generation identification devices
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34. Thank You
For Patient Listening..
4/27/2019