Month: May 2015

The Enigma Machine (Alex Ho)

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The Enigma Machine, created by Nazis in World War II, used
to encode messages ad locations of various Nazi ships. Even if the machine were
to fall into the Allies hands, they would have to guess until the next day,
when the code changed. With the large number of possibilities, it would have
required too man power. Bletchley Park was the place where the code breakers
tried to crack the Enigma, and the Nazis didn’t even know about it.

Looking for common words, regarding the weather conditions
and “Heil Hitler”, Alan Turing came up the idea to look for these words, using
a machine, initially designing the ‘Bombe’. Knowing that letters cannot repeat
themselves, this reduced the number of possibilities.

Over the years as the Allies cracked the Enigma codes using
the Bombe, carefully choosing what information to keep or act upon, in order to
make sure the Nazis do not suspect their “unbreakable” code, was in fact
broken.

#exploremaths

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The Enigmatic Enigma not so Enigmatic (Josh Luong)

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1. What is the flaw Enigma Has?

The problem with eni1. What is the flaw Enigma Has?

The problem with enigma was that when a letter was typed
into the machine, the letter would be matched up with 25 other letters except
for itself. This was a huge flaw as it would eliminate the possibilities for
how the messaged was encrypted. Alan Turing was able to crack this and continued
to use this information along with a device called ” The Bomb” which
cracked the German messages.

 

2. What did the allies do to break it?

The allies had a group of people working on ways to
decryption the hidden messages sent by the Germans. They created an old
fashioned computer comprised of gears and metals that had been connected in
some way to crack the enigma code. This was called “The Bomb” and was
made in Bletchley park in secrecy.gma was that when a letter was typed
into the machine, the letter would be matched up with 25 other letters except
for itself. This was a huge flaw as it would eliminate the possibilities for
how the messaged was encrypted. Alan Turing was able to crack this and continued
to use this information along with a device called ” The Bomb” which
cracked the German plans.

 

#exploremaths

Cryptography problems

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The main problem with this cipher code is that you can easily crack the code of the message by judging the frequency of the message. Example, the word ‘the’ is a word that is unavoidable in a sentence so if the same cluster appears commonly and is in 3 letter format, then this word may just be the letter ‘the’. The problem with the encryption method is once you find out the code, the whole message is clear. A way to tackle the problem is to every letter has a different code. This would make the code harder to crack but and frustrating.
#exploremaths

Substitution Cipher (by Michelle So)

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What is the
problem with the encryption?

The problem
with this substitution encryption is in order for someone to use this code;
someone has to provide the key beforehand. In addition to this, using a
frequency analysis, one can easily decipher the message, as there are some
letters in the English language that occur more than other letters.

How do you
overcome this problem?

To overcome this problem, they could make the
code more complicated by adding an encryption to the key. If there was an
encryption to the key, it would take more time for the enemy to decipher it. Furthermore,
if the key was renew every day, by the time they have decode the encryption,
there would already be another key.  

#exploremaths

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Substitution Cipher (sophia kim)

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CRYPTOGRAPHY.

What is the problem with substitution
ciphers?

Substitution cipher is fairly easy to
decipher using frequency analysis. Frequency analysis is the frequency of each
letter appearing in the cipher.

Ways to make it more difficult are:

Using different languages

Stacking several ciphers together

Using difficult symbols

Switching letters around

#exploremaths 

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or confidential information or both. If you are not the intended recipient
please delete it and notify the sender.

Cryptography: Terrence Wong

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The substitution method has a major flaw in it saying that it can be cracked with frequency analysis. Frequency analysis is the analysis of letters which appear frequently in a message or a text. One way to solve this issue is to replace letters with Greek Letters and manipulate it in a way of making it look miscellaneous. Letters could be replaced with different stroked which have been previously agreed on by the sender and receiver.

i.e. 

You could have one stroke meaning ‘A’, a cross meaing ‘B’, two horizontal strokes and a vertical meaning ‘C’, and so on. 

#exploremaths

The Substitution Cipher [Adam Tan]

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1. What is one problem with the substitution cipher?
One problem with this particular cipher is that it is reeeaaaasonably easy to break using ‘frequency analysis.’ By calculating how many times a certain letter occurs, referencing the frequency of understandable letters allows the decipherer(?) to assume which letters/numbers/symbols correspond to which letters.

2. How can this problem be overcome?

One way to overcome this obstacle is to substitute spaces with a combination of letters (a combination is necessary as a single letter may be confused with another letter. Another method is to place certain symbols after certain letters are written (eg. after every letter ‘A’, you can place an the letters ‘EN’. I received this idea from the beloved series Deltora Quest).

#exploremaths