WHAT FUTURE FORCONTACTLESS CARDSECURITY ?
Alain Vazquez(alain.vazquez@louveciennes.sema.slb.com)
1/27 AV
2001/11/05

Contents)Major contactless features : summary
 Contactless major constraints
 Major security issues
 Tamper resistant device
 Authentication
 Integrity
 Confidentiality
 Security evaluation (CC, PP, …)

 What future for the contactless cardsecurity
2/27 AV
2001/11/05

Contactless IC overview
 Based on Smart Card IC with an RF interface (ISO14443-x)
 Readers supply low impedance electromagnetic field at
13,56 MHz to : Generate power supply for IC Support Clock and data exchange using ASK modulation





Modulation rate : 100% (type A) or 10% (type B)
Communication distance (0-10 cm typical)
High speed serial communication (106 Kb/s – 424 Kb/s)
Anti-collision protocol
Extended operating voltage range (typical 2.7 – 5.5 V)

3/27 AV
2001/11/05

Diagram (dual interface)
ISO contact
Contact
Interface

Security Logic& Sensors

ROM

EEPROM
Microprocessor

Antenna

4/27 AV
2001/11/05

ContactlessInterface
Unit

CryptoProcessor(TDES, RSA, …)

RAMTargeted market

Public TransportBus, Subway,Train

Car Parking

City Services
Library,Swimming
PoolPayphones

Schools
Retail5/27 AV
2001/11/05

Contents
 Major contactless features : summary)Contactless major constraints
 Major security issues
 Tamper resistant device
 Authentication
 Integrity
 Confidentiality
 Security evaluation (CC, PP, …)

 What future for the contactless card security

6/27 AV
2001/11/05

Contactless constraints
 Ability to perform a "transaction" within amaximum of 150 ms time including : Dialogue establishment with the reader (anticollision detection)
 Internal computation (which may include
cryptographic processing) Data exchange (1O6 kb/s) in half duplex

 Low power consumption : typically 2 to 5 mW
 Internal CPU clock Adapted design technology (submicron)
7/27 AV
2001/11/05

Security attacks
Man in the middle
ReaderHost

Eavesdropping

Telepickpocketing
8/27 AV
2001/11/05

Tampering

Contents
 Major contactless features : summary
 Contactless major constraints)Major security issues
 Tamper resistant device
 Authentication
 Integrity
 Confidentiality
 Security evaluation (CC, PP, …)

 What future for the contactless cardsecurity
9/27 AV
2001/11/05

Tamper resistant device Tamper resistant device
 Objectives : to prevent the outside from :z Reading what must be kept secretz Tampering any stored data Contactless attacks
z Most of them are common to "contact only" cardsz Some of them may be re-enforced because ofelectromagnetic radiation (power, clock, data, …)

10/27 AV
2001/11/05

Attacks 1/2
 Attacks (common with contact cards)
 Physicalz Microprobing : access to chip with test or opticalmeans
z Test mode recovery : recover initial test bitstatementz Reverse engineering : layout, data, address
reconstructionz Environmental monitoring ; temperature, light, …

 Electricalz SPA/DPA : statistical attacks based on poweranalysisz Timing : execution time depending on input
parameters and secret data involved

 Logical
11/27 AV
2001/11/05

z Software : taking advantage (through the standardinput) of the vulnerability of OS embedded

Attacks 2/2
 Attacks (re-enforced by RF interface) Electricalz EMA : Electromagnetic Analysis{ Internal chip radiation{ RF radiation (13 MHz range)z Power drops and short cuts (nota){ Available power magnitude highly variable -> chipextended tolerance (2.7 -> 5.5 typical){ Clock supply glitches(nota) intended to corrupt the normal transfer of data between CPUand memory

12/27 AV
2001/11/05

Any countermeasures ? 1/2
 Hardware Strong protection layers (test mode recovery) Random logic design (reverse engineeringrecovery)
 Metal shielding (EMA, light, microprobing, …)
 Tamper sensors to warn the OS against attacks
 On chip filters (glitches, transient signals, …) True random generators
 Unpredictable chip current power consumption

 Software Memory address scrambling/memory
management (firewall) Random software execution
13/27 AV
2001/11/05

Any countermeasures ? 2/2
 Countermeasures efficiency
 To fight against one attack, generally many
countermeasures may be required but :z Additional hardware modules will increase
power consumptionz Additional software will slow the execution
process One compromise must be found between
efficiency and contactless requirements(execution time, power requirements)

14/27 AV
2001/11/05

Integrity
 Definition
 Confidence that the received data stream is
actually the posted stream

 Mechanisms involved depend on the security
level required Basic protocol feature (Data associated with a
CRC check within a frame) eg ISO 14443-4
 Hash code (one way function)z SHA-1 (160 bit code)z MD5 (128 bit code)z Ripemd (160 bit code)
15/27 AV
2001/11/05

Authentication 1/5
 Definition
 Mechanism that allows you to prove who you
are actually Mechanisms (security level dependent)z ID presentation (identification)z Cryptographic techniques{ Symmetrical (DES encryption, MAC, …){ Asymmetrical (digital signature RSA, DSA,ECDSA, …)
Remark : In most cases, authentication and integrity are
performed at the same time
16/27 AV
2001/11/05

Authentication 2/5
 User by the card (theft prevention)
 Not feasible in most casesz No Pin code typingz No biometric mechanisms (e.g. fingerprint)
Nota : If required, authentication can be performed by out ofband mechanisms (ex : railway ticket inspector)

 Card vs reader Typical requirements
 Tranportation : card is authenticated by thereader Finance : mutual authentication is required
17/27 AV
2001/11/05

Authentication 3/5
Card

ReaderID

Card ID posting

ID reading
Randomgeneration

arandom

Master key diversification
Kc

C=TDES(Kc, a)

C’=TDES(Kc, a)
C’C

C= C’
yes
Authentication

BASIC AUTHENTICATION PROCESS USING A SYMMETRICAL
ALGORITHM (CARD AUTHENTICATED BY READER)
18/27 AV
2001/11/05

Authentication 4/5
Card

Reader
Challenge

Hash Function

DigestCardPrivate
Key

Card Certificate

Challenge
CA keyCertificateverification

Hash Function

Public keyDigest

Signatureverification

Signature

Received
DigestCalculated
Digest=yes

Authentication

BASIC AUTHENTICATION (AND INTEGRITY) PROCESS USING
19/27 AV ASYMMETRICAL ALGORITHM (CARD AUTHENTICATED BY
2001/11/05
READER)

Authentication 5/5
 Computation performance (typical)
 TDES encryption (8 bit CPU) TDES/128 bit key
z Software : 80/100 ms
z Cryptoprocessing : 35 µs

 Digital signature RSA / 1024 bit key
z Software : not available at companyz Cryptoprocessing : 85 ms for signature
generation

20/27 AV
2001/11/05

Confidentiality 1/2
 Confidentiality
 Objective : to insure privacy of transmitted data
between card and reader Techniques : Encryptionz Symmetrical key{ Difficult to manage and to share{ Requires a low "computation" powerz Asymmetrical key{ Easy to manage{ Requires a high "computation" power and may require acryptographic coprocessor
21/27 AV
2001/11/05

Security evaluation
 "Contact Only" cards
 Some IC are compliant with CC EAL4
augmented
 Recently, an IC has been announced as
being evaluated EAL5 augmented
 Contactless cards
 Very few products have already beencertified CC (ex : ASK IC with a Slb SAM
software: EAL1+)
 Some Protection Profiles have beencertified (Assurance level targeted is level 4)
22/27 AV
2001/11/05

Contents
 Major contactless features : summary
 Contactless major constraints
 Major security issues
 Tamper resistant device
 Authentication
 Integrity
 Confidentiality
 Security evaluation (CC, PP, …))What future for the contactless card
security
23/27 AV
2001/11/05

Contactless new products 1/2
 New High end products Mifare : Mifare proX : P8RF5016 (dualinterface) ST Microelectronics : ST19XR34 (dualinterface) Infineon : SLE 88CL320 (Preliminary sheet
not yet available)

24/27 AV
2001/11/05

Contactless new products 2/2
 Typical product features Dual interface/ 13,56 MHz, 106 to 424 kb/s/ 10% or 100 %with ASK modulation
 8 bit CPU with 32 Kb EEPROM or more
 On chip crypto processing (TDES, RSA, El Gamal,Elliptic curves, DSS, …)
 Multiple sensors ( voltage, clock, temperature, …)
 Memory management unit (or firewall) True random number generation
 Multi-application capabilities
25/27 AV2001/11/05

Company On going activities
 Schlumberger is involved in many
comities/Initiatives
 ISO 14443 (WG8), ISO 7816
 E-europe (TB3, TB6), ETSI, EESSI, CEN, …
 Full range of OS including a Java platform Pilot projects
 Transport/purse cards (UK, Colombia,Spain, …)
 City Cards (Brazil, Norway, UK) Corporate/company cards (Club Net/ Japan,KPN (Netherlands, Tokyo University, …)
26/27 AV
2001/11/05

Conclusion The future of contactless cards seems tobe : Dual interface to ease multiapplication/multi-services
 High security features thanks to on-card
cryptoproccessing Opened platform OS (JavaCard, Multos…))To allow high security level evaluations,attacks related to electromagnetic radiationmust be investigated in more details (powerattacks, EMA, …)
27/27 AV
2001/11/05