1. The Imitation Game What else did Alan Turing do? Jeff O’Connell Ohlone College www.ohlone.edu/people/joconnell

2. Outline Ciphers and the Enigma Machine (early 1940s) Turing Machines (1936) The Imitation Game (1950)

3. Ciphers and the Enigma Machine

4. ABCDEFGHIJ KLMNOPQRST UVWXYZ

5. ABCDEFGHIJ a KLMNOPQRST UVWXYZ

6. ABCDEFGHIJ abcdefg KLMNOPQRST hijklmnopq UVWXYZ rstuvw

7. ABCDEFGHIJ xyzabcdefg KLMNOPQRST hijklmnopq UVWXYZ rstuvw

8. ABCDEFGHIJ xyzabcdefg KLMNOPQRST hijklmnopq UVWXYZ rstuvw MATHIS A LOTOFFUN

9. ABCDEFGHIJ xyzabcdefg KLMNOPQRST hijklmnopq UVWXYZ rstuvw MATH jxqe IS fp A x LOT ilq OF lc FUN crk

10. Vigenère Ciphers

11. MATH IS A LOT OF FUN

12. OHLO MATH NE IS O A HLO LOT NE OF OHL FUN

13. OHLO MATH NE IS O A HLO LOT NE OF OHL FUN ABCDEFGHIJ 0123456789 KLMNOPQRST 10111213141516171819 UVWXYZ 202122232425

14. OHLO MATH a NE IS O A HLO LOT NE OF OHL FUN ABCDEFGHIJ 0123456789 KLMNOPQRST 10111213141516171819 UVWXYZ 202122232425

15. OHLO MATH ahev NE IS vw O A o HLO LOT szh NE OF bj OHL FUN tby ABCDEFGHIJ 0123456789 KLMNOPQRST 10111213141516171819 UVWXYZ 202122232425

16. The Enigma Machine

17. Used to both encode and decode messages. Initially had 3 wheels that were set each day to a predetermined configuration. (Later, more wheels were added to make it more difficult to crack). As one key was pressed, another would light up giving the encoded (or decoded) letter. Was designed so that a letter never mapped to itself. Δ

18. Turing Machines Turing wrote a paper called “On Computable Numbers, with an Application to the Entscheidungsproblem” in 1936.

19. Turing Machines Turing wrote a paper called “On Computable Numbers, with an Application to the Entscheidungsproblem” in 1936.

20. Turing Machine Tape – Divided into cells. Each cell contains a symbol. A Read/Write Head – Can read and write on the tape and move the tape left and right one (and only one) position at a time. State Register – Stores the “state” of the machine. A finite table of instructions. Video

21. The Imitation Game Computing Machinery and Intelligence written in 1950 by Alan Turing. I propose to consider the question “Can machines think?”

22. It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart front the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman.

23. We now ask the question, "What will happen when a machine takes the part of A in this game?" Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, "Can machines think?" Movie

25. Further Reading/Watching Alan Turing The Man Who Knew Too Much: Alan Turing and the Invention of the Computer Caesar Ciphers https://www.khanacademy.org/computing/computer-science/cryptography/crypt/v/caesar-cipher Vigenère Ciphers https://www.youtube.com/watch?v=9zASwVoshiM Turing’s paper Computing Machinery and Intelligence http://www.loebner.net/Prizef/TuringArticle.html Turing Test http://www.turing.org.uk/scrapbook/test.html http://www.washingtonpost.com/news/morning-mix/wp/2014/06/09/a-computer-just-passed- the-turing-test-in-landmark-trial/ http://www.washingtonpost.com/news/morning-mix/wp/2014/06/09/a-computer-just-passed- the-turing-test-in-landmark-trial/ Turing Machines Explained - https://www.youtube.com/watch?v=dNRDvLACg5Qhttps://www.youtube.com/watch?v=dNRDvLACg5Q The Busy Beaver - https://www.youtube.com/watch?v=CE8UhcyJS0Ihttps://www.youtube.com/watch?v=CE8UhcyJS0I

26. Thank You! Jeff O’Connell Ohlone College www.ohlone.edu/people/joconnell