• Courseworks 7 and 8 are now available. Coursework 7 is entirely electronic: make sure you follow the rules precisely, or my automatic coursework-marking program will not be able to award you any marks.
• The Cipher Challenge is now ready for you cryptanalysts to do your best/worst. (10.43 am Tuesday 20th February)
• 7pm 18/2/07: Of the 85 ciphers submitted, I have managed to check (and in some cases correct) 63 so far. Numbers 7, 26, 35, 53, 65, 82, and 86 need to be sent again, with the excessively long lines broken up into shorter lines, as I did not receive the full ciphertext and/or plaintext and/or explanation. I will be sending individual emails to everyone whose ciphers continue to give me problems, on Monday afternoon. Please check your email frequently!
• 3.30pm 15/2/07; I have collected 87 ciphers from my emails today. You should have received an acknowledgment of your submission by now. Please check your email to see if there was a problem with your submission: I may also discover more problems as I process your files. In particular, many files had excessively long lines which were truncated in transmission.
• I hope to have the challenge web page live by Tuesday 20th February, 10 am.
• I have received more than 120 emails for the cipher challenge. Please be patient and do not expect me to reply to each one immediately!
• I have marked coursework 2. Once I have entered the marks into SID the courseworks will be available for collection.
• Coursework sheet 4 is now available on the link below, as are Solutions 2 and 3.
• Coursework sheet 4 has been postponed until after the Cipher Challenge. New deadline is Week 8 instead of Week 6.
• Apologies for the delays in getting coursework marked and returned to you. This is because the allocated markers are not doing it, for various reasons. I am trying to get this sorted out as quickly as possible. Unfortunately there are not enough hours in the week for me to do all the marking myself!
• The worked example from Lecture 5 (breaking an affine cipher) can be found on page 12 of Notes 2 (see link below).
• Here is the worked example of breaking a substitution cipher, done in Lecture 3.
• I may have inadvertently given the impression that because there are lecture notes on this web-page, attendance at lectures is somehow optional. This is a misguided view. Lectures provide you with learning experiences and opportunities that you cannot get from reading the notes. Not everything I say in the lectures is written down in the notes, and I will often present things in a different way in the lectures from the way they are presented in the notes. If you choose not to attend the lectures you must recognise that you are putting yourself at a potentially serious disadvantage.
• Coursework should be handed in to the RED box on the SECOND floor.
• For back-up here is a link to last year's web-pages.

• Course Description from the Maths UG Handbook
• Course information sheet (PDF file)
• Key objectives and exam rubric
• 2005 exam paper

Notes

• Notes 1: Introduction
• Notes 2: Substitution ciphers
• Notes 3: Stream ciphers
• Notes 4: Stream ciphers, continued
• Notes 5: Stream ciphers, concluded
• Notes 6: Public-key cryptography
• Notes 7: Public-key cryptography: RSA
• Notes 8: Public-key cryptography: Primes and factorisation
• Notes 9: Public-key cryptography: El-Gamal
• Notes 10: Public-key cryptography: Other ciphers
• Notes 11: Secret sharing and other matters
• Notes 12: Quantum effects; bibliography

Coursework

• Coursework 1, and Solutions
• Coursework 2, and Solutions
• Rules for the cipher challenge
• Coursework 3, and Solutions
• Coursework 4, and Solutions
• Coursework 5, and Solutions
• (corrected) Coursework 6, and Solutions
• Coursework 7. You will also need my RSA public key. No solutions.
• Coursework 8, and Solutions

Other course material

• Here is the worked example of breaking a substitution cipher, done in Lecture 3.

The recommended book for reading before taking the course is Simon Singh's The Code Book; the recommended course text is Douglas Stinson's Cryptography: theory and practice (unfortunately, Paul Garrett's Making, Breaking Codes is out of print). (See below for bibliographical details.)

• Here is the list of ASCII 7-bit codes, and here are the International Telegraph Codes.
• Here are three samples of random text matching the letter, digram and trigram frequencies in a piece of English text (Lewis Carrol's Alice's Adventures in Wonderland).
• Here is "FISH and I" by W. T. Tutte (one of the Bletchley Park codebreakers).
• Here is the Trinity College Historical Cryptography website.
• Here is a collection of Maple lessons on topics in cryptography from Adept Scientific, which can be downloaded free of charge.
• Here are some lecture notes by Peter Cameron on computational complexity.
• Here are John Preskill's Caltech notes on quantum computing.

• General:
  • Henry Beker and Fred Piper, Cipher Systems: The Protection of Communications, Northwood Books, London, 1982.
  • Robert Churchhouse, Codes and Ciphers: Julius Caesar, the Enigma, and the Internet, Cambridge University Press, Cambridge, 2002.
  • Paul Garrett, Making, Breaking Codes: An Introduction to Cryptology, Prentice-Hall, Upper Saddle River, 2001.
  • Simon Singh, The Code Book: The Secret History of Codes and Code-Breaking, Fourth Estate, London, 1999.
  • Douglas R. Stinson, Cryptography: Theory and Practice (2nd edition), Chapman & Hall/CRC, Boca Raton, 2002.
  • John Talbot and Dominic Welsh, Complexity and cryptography: An introduction, Cambridge University Press, Cambridge, 2006.
  • Dominic Welsh, Codes and Cryptography, Oxford University Press, Oxford, 1988.
• Historical:
  • Helen Fouché Gaines, Cryptanalysis: A Study of Ciphers and their Solution, Dover Publ. (reprint), New York, 1956.
  • F. H. Hinsley and Alan Stripp (eds.), Code Breakers: The Inside Story of Bletchley Park, Oxford University Press, Oxford, 1993.
  • Andrew Hodges, Alan Turing: The Enigma, Vintage, London, 1992.
  • Leo Marks, Between Silk and Cyanide: The Story of SOE's Code War, HarperCollins, London, 1998.
  • Doron Swade, The Cogwheel Brain: Charles Babbage and the Quest to Build the First Computer, Little, Brown & Co., London, 2000.
  • Gordon Welchman, The Hut Six Story: Breaking the Enigma Codes, M & M Baldwin, Cleobury Mortimer, 1998.
  • Peter Wright, Spycatcher: The Candid Autobiography of a Senior Intelligence Officer, Stoddart Publ. Co., Toronto, 1987.
• Fictional:
  • Sir Arthur Conan Doyle, The Adventure of the Dancing Men, in The Complete Sherlock Holmes, Penguin (reprint), London, 1981.
  • Edgar Allan Poe, The Gold-Bug, in Complete Tales and Poems, Castle Books, Edison, NJ, 1985.
  • Dorothy L. Sayers, Have His Carcase, Victor Gollancz, London, 1932.
• Related topics:
  • Richard Feynman, The Character of Physical Law, BBC publications, London, 1965.
  • M. R. Garey and D. S. Johnson, Computers and Intractability: A Guide to the Theory of NP-Completeness, Freeman, San Francisco, 1979.
  • Ray Hill, A First Course in Coding Theory, Oxford University Press, Oxford, 1986.
  • Michael A. Nielsen and Isaac L. Chuang, Quantum Information and Quantum Computation, Cambridge University Press, Cambridge, 2000.
• Miscellaneous:
  • G. Mander (ed.), wot txters hav bin w8ing 4, Michael O'Mara Books, London, 2000.
  • Georges Perec (translated by Gilbert Adair), A Void, Harvill Press, 1994.
  • Ernest Vincent Wright, Gadsby, Wetzel Publishing Co., Los Angeles, 1931.

Robert A. Wilson
(based on Peter Cameron's original page)
Created 5 January 2005
Updated 20 March 2007