Inner Workings of the German Enigma

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Inner Workings of the German Enigma
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History of the Enigma

• The concept was invented by a German named Albert
  Scherbius in 1918
• Scherbius tried to take the machine to the German
  military but initially they werent interested
• A company called Gewerkschaft Securitas bought
  the patent in 1920 and started manufacturing the
  Enigma
• The German military became interested in 1925 in
  order to encrypt radio messages.
• The military made some enhancements.

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What is the Enigma

• The Enigma is an Electro-Mechanical Device used
  to Encrypt Messages
• The Mechanical properties of the machine were
  based around gears that would turn as keys were
  pressed on the typewriter style keyboard
• The keyboard would also active electrical
  switches that would initiate an electrical
  current from a battery

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Components of the Enigma

• Keyboard
• Plug Board
• Set of 3 Rotors
• Reflector
• Light Board

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Enigma Keyboard

• Typewriter Style Keyboard Used to enter the
  plaintext message into the machine.

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Enigma Plug Board

• Plug Board Used to make connections between
  letters of the alphabet. If a connection was made
  then the letters would be remapped to each other.
  If a connection was made between the letter A
  and M then M would get substituted for A
  and vise versa.

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Enigma Rotors

• Main Component of the Enigma
• Flat disks with 26 electrical connections on one
  face which correspond to the letters of the
  alphabet. The 26 electrical connections were
  mapped to 26 different connections on the
  opposite face of the rotor.
• Every rotor had a different mapping of the 26
  connections
• Early Enigma machines used 3 rotors from a set of
  available rotors. Rotor move in an odometer
  fashion.
• Possible Alphabets 26x26x2617,576
• 3 rotors in 3 positions 3x2x16
• Total Possible Alphabets 17,576x6105,456

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Enigma Rotor Pictures

• Rotor

• Disassembled Rotor

• Set of Rotors

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Enigma Reflector

• The Reflector was a component at the end of the
  array of rotors that would reflect the electrical
  current back through the rotors in the opposite
  direction and through a different route.

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Enigma Light Board

• The Light Board was used to view the cipher text
  that was being produced by the machine.

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How Does The Enigma Work

• The key is the initial settings of the machine.
  Rotors used and in what slot, Plug Board, Etc.

• There are a total of 9 permutations

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Modern Day Enigmas

• Java Based
• http//www.ugrad.cs.jhu.edu/russell/classes/enigm
  a/

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Modern Day Enigmas

• Electronic (Enigma-E Machine)
• http//www.xat.nl/enigma-e/

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Conclusion

• The Enigma was revolutionary in its complexity
  but also in its ease of use.
• The efforts used by Governments to crack the
  Enigma are the basis for modern day cryptography.