Information Security: Please complete the three steps in full for both Ciphers (
ID: 3734550 • Letter: I
Question
Information Security:
Please complete the three steps in full for both Ciphers (3 steps for Shift Cipher, 3 steps for Subsititution Cipher).
If hand written, please be neat with your handwritting. Thanks
Use this tool to help: https://www.simonsingh.net/The_Black_Chamber/substitutioncrackingtool.html
HERE ARE THE THREE STEPS: BELOW
Shift Cipher:
fxxmjbfxltnslymwtzlmymjbttixxmjrjybnymfbtqkbmtmfifajwdlwjfyrnsiytjfymjwzugzymjifwjistygjhfzxjtkxtrjbttihzyyjwxbtwpnslsjfwgdnsymjktwjxymjfxpjimjwbmjwjxmjbfxltnslymjuttwhmnqibmtinistypstbymfynybfxifsljwtzxytxyfdfsiyfqpytfbtqkxfniytmnrnfrltnslytxjjrdlwfsirtymjwfsi hfwwdmjwfhfpjfsifqnyyqjutytkgzyyjwkwtrrdrtymjw
Substitution Cipher:
zorxv dzh yvtrmmrmt gl tvg evib grivw lu hrggrmt yb svi hrhgvi lm gsv yzmp zmw lu szermt mlgsrmt gl wl lmxv li gdrxv hsv szw kvvkvw rmgl gsv yllp svi hrhgvi dzh ivzwrmt yfg rg szw ml krxgfivh li xlmevihzgrlmh rm rg zmw dszg rh gsv fhv lu z yllp gslftsg zorxv drgslfg krxgfivh li xlmevihzgrlm hl hsv dzh xlmhrwvirmt rm svi ldm nrmw zh dvoo zh hsv xlfow uli gsv slg wzb nzwv svi uvvo evib hovvkb zmw hgfkrw dsvgsvi gsv kovzhfiv lu nzprmt z wzrhb xszrm dlfow yv dligs gsv gilfyov lu tvggrmt fk zmw krxprmt gsv wzrhrvh dsvm hfwwvmob z dsrgv Izyyrg drgs krmp vbvh izm xolhv yb svi
For each cipher: 1. Suggest two different ways of attacking the cipher. Make sure to indicate 2. Explain which of the two ways you would choose to break the cipher and 3. Break the cipher and include the plaintext in your submission along with a which attack scenario applies. why. detailed explanation of how you get the plaintext.Explanation / Answer
Shift Cipher
1.
a)Trial and error method of attack
b)Since the whole text follows the same shift key,it is easier to break once the one
seems to apply.
2.I would like to go with the trial and error method which can lead to the solution almost
all the times
3.Decrypted text:
as she was going through the woods she met with a wolf who had
a very great mind to eat her up but he dared not because of some woodcutters
working nearby in the forest he asked her where she was going the poor child who did not
know that it was dangerous to stay and talk to a wolf said to him i am
going to see my grandmother and
carry her a cake and a little pot of butter from my mother.
I reached to the plain text by simple trial and error of no.of shifts.I had to try upto key=5.
Substitution Cipher
1.
a)Trial and error method of attack
b)Following the rule of most frequent occurence and decrypting it in that fashion.
2.I would go with the step-by-step procedure of decrypting
the text as it is a systematic approach.You might not be able to decrypt the whole
message but you can definitely get the hint of it.And once you initiate it,you can easily break throgh the cipher
3.ALICE WAS BEGINNING TO GET VERY TIRED OF SITTING BY HER SISTER ON THE BANK
AND OF HAVING NOTHING TO DO ONCE OR TWICE SHE HAD PEEPED INTO THE BOOK HER SISTER
WAS READING BUT IT HAD NO PICTURES OR CONVERSATIONS IN IT AND WHAT IS THE USE OF A BOOK
THOUGHT ALICE WITHOUT PICTURES OR CONVERSATION SO SHE WAS CONSIDERING IN HER OWN
MIND AS WELL AS SHE COULD FOR THE HOT DAY MADE HER FEEL VERY SLEEPY AND STUPID
WHETHER THE PLEASURE OF MAKING A DAISY CHAIN WOULD BE WORTH THE TROUBLE OF GETTING UP
AND PICKING THE DAISIES WHEN SUDDENLY A WHITE RABBIT WITH PINK EYES RAN CLOSE BY HER.
I reached to the plain text by doing frequency analysis initially and then guessing the letters as per the knowledge of the language.