Code Breaking as a Teaching Tool

1. Code Breaking as a Teaching Tool Kelly Jackson CCLR Spring 2011

2. Purpose • The purpose of this workshop is to explore the ways that cryptography can be used as a tool in your classroom to explore curriculum topics in mathematics, language, history and technology.

3. Some Common Codes • Morse Code • ASL Alphabet • Braille Alphabet • Semaphore • International Signal Flags • “Piglatin”

4. Basic Vocabulary • Cryptography • Cipher • Code • Plain text • Encryption • Decryption • Transposition • Null • Substitution • Mono-alphabetic • Poly-alphabetic

5. Cryptography • Greek • Kryptos…hidden • Graphia…writing

6. Encryption • The process used to convert plain text to cipher text • This process is the “lock”

7. Decryption • The process used to change cipher text back to plain text. • This process is the “key”

8. Cipher • “To number” • Each letter of the original text is represented in the coded text.

9. Code • Used colloquially to mean any secret writing. • Technically this means that the entire word or phrase is replaced by another word or phrase.

10. Plain text • The original message • Prior to encoding • Usually written in uppercase

11. Cipher text • The coded text • Term is used regardless of the method of encryption • Usually written in lowercase italics

12. Basic Cipher Techniques • Transposition • Null • Substitution • Special Cases • Telephone Cipher • Pigpen Cipher • Checkerboard Cipher • Sir Francis Bacon Cipher • Playfair Cipher

13. Transposition Ciphers • All of the letters in the original source message remain, but in a scrambled order. • Split Rail • Backward • Column • Routing • Grille

14. Null Ciphers • Extra characters are added to make the message more difficult to decrypt, or more difficult to recognize as a coded message.

15. Substitution Ciphers • Letter order remains the same, but each letter is replaced by another letter or symbol • Mono-alphabetic Ciphers • Shift Cipher • Random substitution Cipher • Cipher Wheel • Poly-alphabetic Cipher • Vignenere • Jefferson’s Cipher Wheel • Code Machines

16. Egyptian Hieroglyphic Ciphers

17. Hebrew Ciphers • ATBASH • Used in Jeremiah • לב קמי Lev Kamai (51:1) is Atbash for כשדים Kasdim(Chaldeans), • ששך Sheshakh(25:26; 51:41) is Atbash for בבל Bavel(Babylon).

18. Spartan Skytale

19. Caesar Cipher

20. India • The Kama Sutra lists cryptography as the 44th and 45th of the 64 arts men and women should know and practice. • 44…The art of writing in cipher, and writing words in a peculiar way. • 45…The art of speaking by changing the forms of words. This could be changing the beginning and ending or by adding extra letters between every syllable

21. Precursor to Pig Latin??? • beast → east-bay • trash → ash-tray • happy → appy-hay • question → estion-quay

22. Mary Queen of Scots/Babington • Lost her head, in part, because of coded messages she allegedly sent and received.

23. Cardinal Richelieu Cardan Grille (Named for Cardano)

24. Louis XIV…The Man in the Iron Mask • Great Cipher or Grand Chiffre was a nomenclator cipher developed by the Rossignols, several generations of whom served the French Crown as cryptographers

25. Revolutionary Codes Pigpen Cipher AKA Freemason’s Cipher

26. b e n b e n b e n b e n b e n b e n b b o t h m u s t k n o w k e y w o r d 26100606080717152312100909261121100402

28. Jefferson Cipher Wheel Online Jefferson Cipher Wheel

30. Robert Patterson Mathematics Professor University of Pennsylvania

31. Lewis and Clark

32. Civil War Era

33. Confederate Cipher Disk

34. Underground Railroad Quilt

35. Depression Era “Hobo Code”

36. Depression Era “Hobo Code”

37. Enigma

38. Purple

41. Modern Encryption