Material Detail

The Enigma Machine

The Enigma Machine

An applet that demonstrates the operation of the code-breaking Enigma machine.


  • Editor Reviews
  • User Rating
  • Comments  (4) Comments
  • Learning Exercises
  • Bookmark Collections
  • Course ePortfolios
  • Accessibility Info

More about this material


Log in to participate in the discussions or sign up if you are not already a MERLOT member.
Rodney Peterson
Rodney Peterson (Student)
19 years ago
The third Merlot link I came upon was one desinged by author Russell Schwager.
Schwager?s webpage entitled ?How Does The Enigma Work?? For those who are
history buffs, the Enigma Machine (which has a strong resemblance to a
typewriter) was the device that the Third Reich employed to send and receive
coded messages, during WWII (more recently, the Enigma machine was prominently
shown in the fictional WWII films ?Das Boot? and ?U-571?). For years the
Enigma Code played havoc with the Allies and their ability to crack and be
capable of deciphering the encoded messages. One man, Alan Turing, is credited
with near genius for his successful efforts in cracking the Enigma Code. The
arrogant Germans were over confident in their technology and never realized that
their machine and Enigma codes had fallen into the hands of the Allies.
Consequently, the Allies were enabled to keep track of all the German orders,
field commands, and troop deployment and positions. The curious feature about
Schwager webpage is that a workable applet (facsimile) is displayed which allows
the viewer to work with the machine as it was employed during the war. Another
nice feature about Schwager webpage is its detailed explanation of how all the
components, ?a plug board, a light board, a keyboard, a set of rotors, and a
reflector (half rotor) [were] used in the machine.? Of particular note was that
this machine happens to function quite similarly to our Math G discussion of the
algebra ?input and output? diagram. There are several other links that offer
the viewer the history I encapsulated here, along with multiple links to the
Polish Academic Information Center, Bletchly Park, A Story on the Breaking of
the Enigma Machine, UK Science site with a whole section devoted to
Code-breaking, Another Enigma simulator, Code and Ciphers in WWII, The Code War,
JHU?s Cryptology Class, The Enigma Exhibit at the NSA Museum, Making Magic,
U-Web, The U-BoatWar 1939-45, The Enigma, More on the Enigma, and Think Quest
Entry on Encryption. Encryption has been with humankind for thousands of years.
But for those of us living in the Twenty-first century encryption is common
place, in fact, it is ubiquitous; from military applications, to protecting
intellection property (think Microsoft and its current OS: XP), and computer
privacy (for example, making a purchase online with a credit card). On
Schwager's webpage I read for a couple of hours (made use of several links)
about encryption and the complex mathematical calculations that are routinely
used in everyday software and internet usage, and toyed with the cipher applet
as instructed (which I found fascinating). For students who envision becoming
programmers, Schwager webpage hosts detailed information about how the
encryption process is addressed and employed throughout the world; therefore, I
suspect this somewhat historical as well as current application usages would be
of benefit for math students and their instructors for in-class discussions, and
I can not perceive an instance wherein this webpage would not enhance any
classroom environment. Schwager's webpage appeared to me as having the highest
quality content of the three I have visited thus far. Properly employed by an
instructor, I think that a student?s knowledge of said subject would be
immeasurably enhance, because there is the Enigma applet itself (how it worked),
multiple links that accord consideration of history, applications, and
instruction of the mathematical processes (concepts laid down with easily
comprehendible language). Overall, I was rather impressed, and did enjoy having
my knowledge expanded considerably (I like to understand how things work and
their relationships in the real world). My overall evaluation of the Schwager
webpage, its design and function, should not challenge anyone with the most
basic knowledge and experience with computersand the internet.

Used in course? Yes
Stefan Robila
Stefan Robila (Faculty)
19 years ago
It is an attractive applet that does a great job in implementing the Enigma cipher. It has plenty of options that can be fully used.
From the learning standpoint, the author did a reasonable job in providing some explanation on how the cipher works, how the applet can be used, and also history about the cipher. Unfortunately, it does not look like a standalone teaching tool. The descriptions are rather sketchy and force you to find better sources of information (some provided as links). However, nice visual display, looking close to the real machine.

Technical Remarks:

No difficulties in running the applet (done it on Win2000 / IE5). On the accuracy of the implementation I have only one comment. It seems that the plugboard allows a connection to the same node (i.e. connect A to A). Although this really does not make any difference, it is not fully accurate to the original method. In addition, since each letter can belong to only one connection, having a copnnection to itself makes the node unusable.
Lurraine Rees
Lurraine Rees (Student)
19 years ago
What hooked me on this site was the name "Enigma" and "code breaker". The page
begins with a model of the machine and it was fun to type out an encrypted
message. An explanation follows, along with a description of its components, a
brief history, and links to more sites loaded with information. The best link
was "The Story on the Breaking of the Enigma Machine Code", which is an 8-part
story about Joe Desch, the NCR engineer, who developed the machine to break the
Nazi's codes.
The story recounts how, in 1942, he designed and manufactured high-speed
electronic counters for the code breaker machines at NCR contributting to war
effort. The machines relied on gas tubes ,which he invented, for computations.
By using three rotors, a plug board, keys, and a display board, the
number possible for each letter was 10^23 for three rotors or 10^26 for four
rotors. WOW!
Interestingly enough, these same electronic counters were sent to the Manhattan
Project. Much more information about the enigma machines was recently
declassified, in 1992, by former President Clinton.
This is a fascinating retelling of how this information was discovered by Joe
Desch's daughter.

Technical Remarks:

It was very easy to navigate around the site and to visit other hyperlinks. I
wish there were more demonstration encrypted messages to practice with or
instructions on how to set the rotors, plug board, and key strokes to simulate
the decoding process.
Eliza Bermudez
Eliza Bermudez (Student)
20 years ago
I was rolling the dice on this assignment. I asked a friend to pick a number for
the page, and a number for the material. I had no clue on what the Emigma
Machine was, but as I read along it was very interesting. This machine was a
simple cipher that was used in the WW II by the Germans for military messages,
and it look simular to a typewriter. The machine has several variable settings,
for operation. When a key is is pressed an electrical current is sent and
becomes an encrypted letter.Well the whole encryption process for contains a
minimum of 7 remappings and a max of 9 remappings.The effectiveness was cool,
there was a lot of material and history behind the information. Yes the
information given was easy to understand and thorough .