Alan Turing Presentation

Alan Turing and Co.

Slate Sculpture: Stephen Kettle

1912-1954

Turing’s Path to Artificial Intelligence
• The Enigma • The Turing Machine • The Turing Test • Turing’s thoughts for Artificial Intelligence

The Enigma Machine
• e·nig·ma (n): 1)A person or thing that is mysterious or puzzling. 2)A riddle or paradox. • Originally designed by Arthur Sherbius and sold commercially for banking. • The “Enigma machine” was later adopted by the Germans and made into a Machine used to send coded messages during WWII. • The messages were encoded using the enigma machine and sent via morse code or radio.

The Enigma Machine
The Enigma Machine:
-Steckerboard (Playboard) - 26 keys

-3 or 4 routers
- Battery powered (portable) -Lamp board -Encode and decode messages

Steckerboard (Playboard) and rotors
Steckerboard (Playboard): -Plug connections using a wire - A/C, B/R, Q/P, Z/L etc.

Rotors: -26 rotational positions A-Z, or 01-26 (26 contacts that were wired in different ways for each rotor) - setting the 3 wheels in a certain position was the code for encrypting a message.

Using The Enigma
• Each enigma machine had to have the 3 rotors set in the same position in order to encode and decode message. In order to do this:
1) set up rotors to the specified wheel order for the day.
2) Indicator: Chose 3 letters at random. Type in 3 letters two times to encode message. - Sender: send Indicator and encoded message. - Receiver: with the rotors are set to the specified wheel order - Type in encoded message - set the rotors to the 3 letters that light up on lamp board.  Type in encoded message to get message in plain text. • Important: if the same letter was pressed multiple times, a different letter would light up on the lamp board each time. *This proved to be the weakness of the Enigma machine.*

Sample Enigma Message
1) Set the rotors to the correct position type the letters twice 1) Enter the message received and record letters that light up on