I hope you enjoyed Ed’s guest posts on NP-complete problems on TV the last couple of Mondays. It’s always great to hear from others on math that they are thinking about. This week it’s me again, and ...

CHICAGO — Julius Caesar is said to have encrypted battle plans in an alphabetical code, protecting the life-or-death messages from spies. That wouldn’t work today. Middle school students can easily ...

Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

Mathematics can be used to unlock secret codes and ciphers that have challenged humans for ages. So says Rose- Hulman Institute of Technology mathematics professor Joshua Holden. He should know, for ...