Security and Reliability of Smart
Card
Smart HKID Card Forum
Jan 6, 2001
Science Museum
Dr LM Cheng
Director
Smart Card Design Center
Dept. of Electronic Engineering
City University of Hong Kong
Content
 Background
 General
Security Features
 Simple Cryptographic Engine
 Encryption Techniques
 Security Standards & Assessment
 Physical & Electrical Reliability
 Electro-static Discharge
Background

Type of Smart Cards
 Worldwide Market
 New Technologies requirement
Types of Smart Card
 Memory
Card
 MPU IC card
 Cryptoprocessor card
 Contactless card
Worldwide Smart Cards Market
Forecast
(Millions of Dollars and Millions of Units)
Data From Frost & Sullivan
New Technologies Required

Data Storage Management - information
protection
 authentication process  biometric: fingerprint, facial features, iris
identification, dynamic signature recognition,
speech recognition
 Advanced encryption methods  Elliptic Curve Cryptography, chaotic
techniques, AES
Basic Internal Structure of
CPU Smart Card
Possible Attacks on Smart
Card

UV or X-ray inspection: use high efficiency UV or
X-ray to inspect the memory areas to extract
important information like PIN, secret key and
public key
 EM analysis: use electron
microscope to inspect the
internal structure of the mask
confusion:
disturb the
power supply/frequency
during PIN verification to
confuse the accurate enter
of PIN and allow access to
the protected memory

duplication: illegal
copying of card content
from one to another

tracking: based on the protocol
exchange between the terminal and the
card to track the sequence of commands
Other possible attracts:
 attract on DES like differentiate methods
 attract on RSA using cyclic properties
General Smart Card
Security Features

Against UV or X-ray inspection:
– Using implementation to avoid visible of
ROM Code

EM analysis:
– Address Scrambling of memories

Against confusion:
– Low/High voltage sensors
– Low/High Frequencies sensors
– High Frequency Protection

Against duplication:
– Security PROM Hardware Protected
– Unique Chip Identification Number
– Move Code Blocking

Against Tracking:
– Secure authentication and data/key encryption

Against DPA:
– Random Wait State (Advance)
– Current Scrambling Generator (Advance)

Against Cyclic properties:
– No simple solutions
Protection Against Tracking

Random Number Generator for dynamic
key generation
 Cipher Engine for data protection:
– Block
– Stream
Random Number Generator

For generation of session keys
 Digital approach can only generate pseudo
random number based on
Xi =(a Xi-1 + b) mod c
 Other use analogue approaches like VCO,
white noise generator etc.
Block Cipher
K1 : 16bit
K2 : 16bit
DataIn

DataOut
Block Cipher
8-bit
8-bit
Block Cipher Method –
Write to Memory
K1 : 16bit
K2 : 16bit
DataOut
8-bit
DataIn
Block Cipher
8-bit
Block Cipher Method – Read
from Memory
K1: Master Key of
length 16-bit
 K2: Card ID of length
16-bit
 Process in block and
errors propagate
within the block
Stream Cipher
•
K1 : 16bit
K2 : 16bit
Stream Cipher
DataIn
8-bit
DataOut
8-bit
Similar to a state
machine with K1K2 as
the initial state
• A pseudorandom
number sequences
generated are XOR
with the Input Data to
form the Output Data
• The data must be in
sequence in order to
encode and decode
correctly
Encryption Techniques

Encryption
– Encryption will modify data into irregular form
for security storage and transmission. The
reconstruction is achieved by using a set of
relevant Keys.
 Two cryptosystems are currently being used, i.e.
symmetric (DES/FEAL) and asymmetric (RSA,
ECC). Symmetric cryptosystem requires only one
common key for encryption and decryption
whereas asymmetric system requires two keys, i.e.
private/user key and public/system key.
Common Encryption
Techniques in Smart Card
Private:- Data Exchange
– DES (Data Encryption Standard)
Public:- Key Exchange
– RSA (Rivet, Shamir, Adleman)
– ECC (Elliptic Curve Cryptography)
Also for Authentication
Is Smart Card Secure?

There are no perfect (100%
secured) systems available
 Systems design and built for
minimal attack risk can be treated
as secure sytems
Secure
systems are evaluated/classified in
different levels using international standards such as
TCSEC/DoD (Orange -USA), ITSEC (Europe) and
CCITSE (ISO15408)
Trusted Computer Security
Evaluation Criteria – USA(DoD)

D: Minimal protection
– No protection
C1: Discretionary Security
–Use control access
Protection
C2: Controlled Access Protection
–Use accountability/auditing

B1: Labeled Security Protection
– Use sensitivity (classification) labels

B2: Structured Protection
– Use formal security policy more resistant to penetrate

B3: Security domain
– Highly resistant to penetration. Use security
administrator, auditing events and system recovery
process

A1: Verified protection
– Highly assure of penetration. Use formal specification
and verification approaches.
Information Technology Security
Evaluation Criteria (ITSEC) and Common
Criteria (CC) – Europe&Canada

EAL1 - functional tested
 EAL2 - structurally tested
 EAL3 - methodologically tested and
checked

EAL4 - methodologically designed, tested
and reviewed

EAL5 - semi formally designed and tested
 EAL6
- semi formally verified designed
and tested
 EAL7
tested
- formally verified designed and
Federal Information Processing
Standards (FIPS) - evaluation

FIPS 46-2 and 81 for DES
 FIPS 186 for Digital Signature
 FIPS 140-2 for Cryptographic Modules
Security evaluation
requirements

Cryptographic modules
 module interface
 role and services
 finite state machine model
 physical security
 Environmental Failure Protection/Testing
(EFT/EFP)

Software security
 Operation security
 cryptographic key management
 cryptographic algorithm
 EMI/EMC
 self tests
Physical & Electrical Reliability
Test
Standard
Reference
Test Methodology
Test Frequency
1 Salt
Atmosphere
CECC 90
000
48 h, 35°C,
45%HR, 5% NaCl
Manufacturing
product audit
2 Insertion
Test
Bull
10 000 insertion
Manufacturing
product audit
3 Data
Retention
Semiconductor
Std.
10 years
Manufacturing
product audit
4 ESD
Protection
MIL STDClass 3: 4Kv
883C Mtd. 8
Chip Characterization
Electro-static Discharge –
Dry/Wet weather comparison
ESD – failure in various stages
Reliability of Contact Type
Smart Card Reader
Mechanical Insertion Life time – around 13x105 insertion
 For a typical flow of 105 crossing per day
 Each reader will only last for 3 days
 Assuming 30 readers installed at border, all
readers have to be replaced in 90 days.
 Whereas, contactless type has MTBF over
115,000 hrs = over 13 years

Conclusion

Smart Card is an evolutionary product
 Trend of use is irreversible
 HKID project can built a framework to
make it smart
 More technology breakthrough is needed to
make them really multi-applications
 Technology is fact but not miracle