E&CE 710 Topic 4 (ECE 716)

Sequence Design and Cryptography

Fall  2005

Contents and Approximate Schedule

More examples and details will be provided in class.

· Topic: Introduction to Sequence Design and Cryptography

Part I: Sequence Design

· Topic 1. Introduction to mobile security: security principles, objectives, and threats, and security architecture.

· Topic 2. Finite fields: group structure, finite group, order, finite fields $GF(p)$ and $GF(2^n)$, minimal polynomial, subfield, and trace function.

· Topic 3. Feedback shift register sequences (LFSR), randomness measurements, linear span and the Berlekamp-Massey algorithm.

· Topic 4. Design of sequences with 2-level auto correlation: m-sequences, quadratic sequences, GMW sequences, three-term sequences, five term and WG sequences, and examples of orthogonal code design.

· Topic 5. Design of sequences with low cross correlation sequences: interference and intraference in CDMA signal detections, Gold-pair sequences, Kasami sequences, interleaved sequences, $Z_4$ sequences, and signal sets for 3G.

· Topic 6. Design of pseudo-random sequence (number) generators: filtering generators, combinatorial function generators, clock-control generators, shrinking generators, and Blum-Blum generators.

Part II. Cryptography

· Topic 7. Symmetric key cryptography: one-time-pad, examples of stream ciphers (A5 and W7), stream cipher candidates from ECRYPT (WG, Achterbahn), DES (Data Encryption Standard), AES (Advanced Encryption Standard) RIJNDAEL, encryption models, hashing functions and MAC (message authentication code).

· Topic 8. Digital signatures: security of public-key cryptography, RSA encryption and digital signature, ElGamal digital signature, DSS (Digital Signature Standard) and ECDSA (elliptic curve digital signature algorithm).

· Topic 9. LFSR public-key cryptography: LUC, GH and XTR Diffie-Hellman key agreement protocol and digital signature schemes.

Part III. Security Practice: Mobile Security

· Topic 10. Privacy in wireless systems: secure tunnel, security of stream ciphers in WEP and 3G (RC4, E0), privacy of CDMA systems (CDMA IS-95, W-CDMA), and block ciphers used in stream cipher mode (Kasumi in 3G, AES in wireless LAN).

· Topic 11. Key distribution, management and certification – symmetric key approach: adversary model, kerboros, and authentication in cellular communication systems (SIM card in UMTS, signature sequence in CDMA).

· Topic 12. Key distribution, management and certification -- public-key approach: pre-authentication, authenticators for unauthenticated model, key transport and key distributions, X.509 strong authentication protocols, station-to-station protocols, IKE (Internet key exchange) protocol, PGP and Verysign certificates, and light authenticated key exchange protocol.