Eventually, I'll port this to HTML, but at the moment it is only available as PDF or, for those who want to remix, in the original L^AT_EX source.

Here is the PDF version.

And here are the files one needs to make this with L^AT_EX:

1. The actual source: funwithcrypto.tex.
2. Required image files:
   1. CC-BY.pdf
   2. gauss.pdf
   3. greece_map.pdf
   4. rome_map.pdf
   5. Scytale.pdf
   6. world_map.pdf

In addition, the following files have examples the group was intended to download for some active engagement:

1. caesar.html
2. challenge.html
3. ciphertext.html
4. harder.html
5. histo.html

On my machine, which is running Linux Mint "18.3 (Sylvia)" and which has a quite complete suite of texlive packages (including, crucially, texlive-base and texlive-latex-base; other required L^AT_EX packages will be obvious to anyone who knows L^AT_EX when looking at the \includepackage commands in the funwithcrypto.tex source file), at the command line, I do the following in a directory containing the above files:

          pdflatex funwithcrypto
          pdflatex funwithcrypto
      

If you want just to download one archive with all of those files in it, you could use either of the following two choices:

• funwithcryptoFiles.tar — a tar archive, for Linux users
• funwithcryptoFiles.zip — a zip archive, for users of other operating systems