and Cryptography Smart Cards: An Overview
Parviz Kermani IBM- Watson Research Center Yorktown heights, NY 10598
Motivations for Cryptography
Websters definition:
The art of writing or deciphering messages in code The system used in a code or cipher
Historical importance
It all started with military needs Early secrecy in dissemination of information Recent advances in computer communication
Explosion of the of Internet E-commerce
Emergence of a (relatively) new technology Smart Card
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A (Network) Security Model
Alice Trusted Third Party Bob
Message
Secret Info
Message
Secret Info
Security Related Transformation Ciphertext Information Channel
Security Related Transformation Ciphertext
Intruder
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Symmetric Encryption
Alice Bob
Plaintext
Secret Key & IV
Plaintext
Secret Key & IV
Security Related Transformation Ciphertext Information Channel
#%
Security Related Transformation Ciphertext
Secret-Key Encryption Highest performance Requires secure key distribution
Intruder
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Symmetric Algorithms
Confidentiality
DES (FIPS 46) Triple DES 56-bit key 112- or 168-bit key
Integrity
DES MAC (FIPS 113) 56-bit key
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Asymmetric Encryption
Alice
Certificate Storage Alice Apub Bob Bpub Robert Rpub . .
Bob
Plaintext
Bpub
Plaintext
Bpriv
Security Related Transformation Ciphertext Information Channel
#%
Security Related Transformation Ciphertext
Public-Key Encryption Slower than secret-key Mainly for digital envelopes, key management, and signature
Intruder
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Public Key Algorithms
Signature
RSA DSA Elliptic Curve (ECDSA)
Key Management
RSA Diffie-Hellman Elliptic Curve
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Key Management
How do Alice and Bob get the same symmetric key? Key management using asymmetric cryptography.. Alice make use of key K and encrypts it with Bobs public key
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Authentication: General Model
I want to intrude and snoop
Trudy Alice Bob
I need to talk to B
Im A Im B If you are A, solve this challenge I know how to authenticate him
What happened?!
I am talking to B and we have a secret key
I am talking to A and we have a secret key
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Digital Certificates
Bind an identity to a public key Built by an issuing or certifying authority, and contain:
Subjects Name Subjects Public Key Issuers Name
Digitally signed by the issuer so that the content cannot be changed
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What a is Smart Card
A normal plastic card with a small microprocessor Chip embedded in it
no internal power. Must be connected to a reader for operation
ISO standards for
Physical parameters Electronic parameters Protocols Low-level command/responses
54 mm (2.13 inches)
IBM
85 mm (3.35 inches)
on cti Thickness: un tiF ard 0.8 mm ul C (0.32 inches) M
Smart Card Standard Dimensions
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History, Background & Types
Invented in the 70s by Moreno, Dethloff, and others Perfected in the 80s by Bull, Schlumberger, SGSThompson, Gemplus, and others
Types of Smart Card Magnetic Cards
3 Track Analogue Tens of bytes Usually disposable No processing capability Used ofr telephone, bus, purse Low cost, <$1.00
Smart Cards
Serial memory (100 to 16k) Microprocessor/Co-processor Secure- Very difficult to clone Intelligence- Can do processing Easily writable & refillable Supports shared key security (DES) Medium Cost ($1 to $5)
Public Key Cryptography Cards
Adds security features Authentication integrity Nonrepudiation Higher cost ($5 to %15)
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Current Smart Card Chips
Processors: clock up to 20 Mhz
Intel 8051, Motorola 6805 (8-bit), Hitachi H8 16-bit processors available but not popular 32-bit processors in horizon
16K Mask ROM for program 2-8K EEPROM for non-volatile storage 256-512 bytes RAM Serial I/O (9600 baud +up) Optional math assist for private/p...