Reply To: Programming

[T]

I found this introduction to number theory:
https://www.southampton.ac.uk/~wright/1001/Notes.pdf
Chapter 9 has information on methods of attacking classic ciphers (most of the methods can be found on various websites so writing you own code would just be for fun).
You don’t need to read the maths in the earlier chapters to write some code based on chapter 9, however the maths is interesting.