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Trinity College Dublin

TCD Mathematics

School of Mathematics

W. F. C. (Michael) Purser

I am an honorary lecturer in mathematics at TCD. For a number of years I have been lecturing to Sophister students of Mathematics, in alternate year on error correcting codes and on cryptology.

Lecture notes

Error Correctiong Codes (2012)

A five-week course on Error-Correcting Codes is scheduled for spring semester 2012.

Here is an outline of the lectures in pdf and in Word formats


The following notes for the course on cryptology were assembled, corrected, retyped and generally beaten into shape by Christina Ruddle. I am extremely grateful to her. All mistakes are mine not hers.

These notes pertain to a course I last delivered in 2008-09 and which I expect to offer again in 2010-11. The previous module code was 374.

  1. Intro and Background
  2. Symmetric Encryption Algorithms
  3. Modular Arithmetic
  4. Public Key Cryptology - Part I
  5. Public Key Cryptology - Part II
  6. Hash Functions
  7. Random Numbers
  8. Factorising and Finding DL
  9. Factorising and DL Using a factor base
  10. Elliptic Curves
  11. DCA
  12. LCA