Week 11Secret Codes of the Middle Ages Compiled by Amy
Steganography • Hides the existence of the message. • This can use “invisible ink”
Cryptography - Transposition • Makes the Messge hard to read. • Use transposition by rearranging the letters.
Cryptography - Substitution • Code • Substitutes a word or idea • Cipher • Substitutes by letter • Monoalphabetic uses one letter to equal one symbol • Polyalphabetic uses several possible symbols to represent one letter • Homophonic – some letters have several choices • Cipher Polybius Square
Polyalphabetic Substitution http://crypto.interactive-maths.com/polyalphabetic-substitution-ciphers.html
Cryptex • Made up by Dan Brown in the Davinci Code! • It is like a bicycle lock and if you get it wrong… • It will release acid that will destroy the message.
Some Unbreakable Codes http://www.newscientist.com/special/unbreakable-codes
Making Your Own Cypher! http://hldennis.com/secrets-to-break/secrets-to-break-book-three/
Cool Websites • http://www.stringpage.com/other/crypto.html • http://www.ciphermysteries.com/2008/06/01/codes-and-ciphers-through-the-middle-ages • http://www.kidsmakestuff.com/articles/show/18hm