I was asked to give some lectures to about 100 high school students
attending the New Jersey Governor's School of Engineering and
Technology during July, 2001. I was glad to do this. Here are notes of
the lectures. Both the notes and the lectures were prepared in a
hurry. The lectures almost followed the notes, but there are more
scholarly details in the notes (including references for those readers
who may be ambitious!). Readers should tell me of errors or bad
writing, please.
At this time it is difficult to write mathematical formulas and notation using standard HTML. Therefore material is presented here in two formats, Postscript and PDF. I hope that everyone can read at least one of these. Now (7/24/2001) improved, with student corrections included! 
What is it?  Links  Last changed 

Lectures 0 & 1 & 2  [Postscript]  [PDF]  7/28/2001 
Lecture 3  [Postscript]  [PDF]  7/24/2001 
Lectures 4 & 5  [Postscript]  [PDF]  7/24/2001 
The titles of the lectures are: 0. Historical and Social Context 1. Secret Sharing 2. Modular Arithmetic 3. Fermat and Euler 4. Public Key Encryption 5. How Hard is Arithmetic? 
