Linguistics 496

Language and Codes Syllabus

Course Description

Goals	This course explores the relationship of cryptography --- the mathematics of hiding information --- with codes, the best human invention for transmitting it.
Practice	The required text is Decrypting Cryptography. Most assigned readings are from there. There is also some course software available from the course website. Use of the software is never required to complete assignments or exams, but it should help make some of the course concepts clearer. Readings, homework, discussion, midterm, term paper.
Concepts	Language, linguistic levels, ciphers, monoalphabetic and polyalphabetic ciphers, ciphers in other writing systems, codes, keys, public key cryptography, RSA protocol, group theory, modular arithmetic. Zero-knowledge proofs. Digital cash. Language as a code. Information-hiding and linguistic levels. Grammars as the keys to language codes.
Office Hours	Tu Th 4:00-5:30, BAM 321

Weekly Syllabus

WEEK ONE Sep 8		Readings	Chapter 1, Cryptography Decrypted. Privacy, Information and Anonymity in the Information Age. Basic concepts of information-hiding. Lecture. Ciphers. Transposition ciphers (Caesar's cipher). Encoding and encipherment. Modular arithmetic, first appearance. Lecture.
		Assignment	NO assignment.
WEEK TWO Sep 15		Readings	Chapters 2, Cryptography Decrypted. Affine ciphers. A little more modular arithmetic. Lecture. General substitution ciphers. The concept of a key.
		Assignment	Shift and affine cipher problems.
WEEK THREE Sep 22		Readings	Chapters 3, Cryptography Decrypted. Discussing affine cipher problem: The concept of an inverse. The concept of a valid cipher system. Vigenere's Cipher. Lecture. Answers to assignment. Hill's cipher. Polyalphabetic vs monoalphabetic cipher. Transposition ciphers.
		Assignment	Vigenere assignment. Hill cipher decoding problem.
WEEK FOUR Sep 29		Readings	Decryption lecture Decryption workbook (includes directions for using computational tools). Frequency lecture Decrypting Vigenere. Chapters 4,5. Cryptography. Breaking a cipher. Breaking substitution ciphers. Data Encryption Standard (DES).
		Assignment	Decoding problem. Crack the secret cipher!
WEEK FIVE Oct 6		Readings	Discussion of decoding problem. Decoding Vigenere's cipher. Ciphers in other writing systems. A Japanese cipher. Lecture.
		Assignment	Hiragana and Code difficulty assignment.
WEEK SIX Oct 11		Readings	No readings. Language as a code. Decoding Egyptian Hieroglyphs and Linear B. Lecture Speech recognition. Claude Shannon's Machine Translation memo.
		Assignment	Playing with Linear B.
WEEK SEVEN Oct 18		Readings	Chapters 7, 8 Cryptography Decrypted. One-way functions. Honest games. Verification and authentication. Non-repudiation. Lecture and reading.
		Assignment	(a) Cheating at honest games. (b) Defeating public key cryptography. (c) Forging digital signatures.
WEEK EIGHT Oct 25		Readings	Chapters 9, 10, 11 Cryptography Decrypted. Public Key Cryptography Diffie Hellman. Modular arithmetic: powers and roots. Inverses. A simple symmetric key code. Euclid's algorithm: a way of finding inverses.
		Assignment	Chapter 3, Section 1Groups, Modular Arithmetic, and Cryptography. Modular multiplication, powers, and roots. Inverses.
WEEK NINE Nov 1		Readings	An example of groups. (pdf, ps). Appendix A, Cryptography Decrypted. Chapter 12, Cryptography Decrypted. RSA. The math. The advantages.
		Assignment	Take-home Midterm.
WEEK TEN Nov 8		Readings	Chapter 2, 3.2, Groups, Modular Arithmetic, and Cryptography. Why it works. Part I: introduction to group theory.
		Assignment	Assignment for Thursday, November 10: Groups and Modular arithmetic.
WEEK ELEVEN Nov 15		Readings	Chapter 2, 3.2, Groups, Modular Arithmetic, and Cryptography. Part II: The theorem of La Grange. Fermat's little theorem. Euler's theorem. RSA: Basic computations, verification, and signatures.
		Assignment	Group theory problems. Are Sudoku squares groups? Modular arithmetic groups under addition and multiplication.
WEEK TWELVE Nov 22		Readings	Zero-knowledge proof. Lecture. Digital cash: The concept. Digital cash: the protocol. Lecture.
		Assignment	Assignment.
WEEK THIRTEEN Nov 29		Readings	Consequences. Cyberpunks and public anonymity. Crypto-Anarchy and Virtual Communities. Tim May. Lecture/outline for Crypto-Anarchy and Virtual Communities. Happy Thanksgiving.
		Assignment	Describe how a hit man might set up shop using (a) an internet bulletin board that anyone can post publicly viewable messages to; (b) RSA cryptography; (c) digital cash. What's the bug? Why isn't this a huge social problem?
WEEK FOURRTEEN Dec 6		Readings	Language as code. The multi-layered structure of language. Grammar as key.
		Assignment	TBA.
WEEK FIFTEEN Dec 13		Readings	Finale.
		Assignment	Take home final.

Place and Time

TuTh 1100-1215 Room: NE-172

Contact

Mailing address:
Department of Linguistics and Oriental Languages
San Diego State University
5500 Campanile Drive
San Diego, CA 92182-7727
Telephone: (619) 594-0252
Office location: BAM, room 321
Office Hours: Tu Th 4:00-5:30