Inner Workings of the German
Enigma
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 weren’t
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.
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
Components of the Enigma
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Keyboard
Plug Board
Set of 3 Rotors
Reflector
Light Board
Enigma Keyboard
• Typewriter Style Keyboard – Used to enter the
plaintext message into the machine.
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.
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 26x26x26=17,576
• 3 rotors in 3 positions 3x2x1=6
• Total Possible Alphabets: 17,576x6=105,456
Enigma Rotor Pictures
• Rotor
• Disassembled Rotor
• Set of Rotors
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.
Enigma Light Board
• The Light Board was used to view the cipher text
that was being produced by the machine.
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
Modern Day Enigma’s
• Java Based
• http://www.ugrad.cs.jhu.edu/~russell/classes/enigma/
Modern Day Enigma’s
• Electronic (Enigma-E Machine)
• http://www.xat.nl/enigma-e/
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.