We recently had a rainy weekend interrupt our original plans to go geocaching. Instead, I took inspiration from John Baichtel's recent posting - Codes For Kids - to introduce my kids to ciphers.

The mechanics of the Double Playfair are involved enough that it is expected that solving this cipher would be most readily achieved by a computer program that recovers the first square by shifting ...

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 ...

PARIS, April 24 (UPI) -- A French computer science student can cipher the 13th root of a 200-digit number in his head -- in less than 9 minutes. Twenty-four-year-old Alexis Lemaire has spent four ...