Cybersecurity Coursework Example | Topics and Well Written Essays - 1000 words

Cybersecurity - Coursework Example The N-gram list of Caesar encryption of the document itself would be the most effective for a cryptanalyst to use to decipher a text encrypted with the Caesar cipher as it shows the frequency of each character used in the document. As E is the most commonly used letter of the alphabet, seeing that the highest frequency letter is H with 148 different instances of the letter would indicate that H is the substitute for the letter E. With this known, it can be seen that there is a shift of 3 present in this particular cipher. Once that has been determined, it would be a simple enough task to pair up all the other letters with their associated substitutions, and then translate the document back to its original text. Q2. What do you notice about the histogram results when text is encrypted with the Vigenere cipher in comparison to the results of the Caesar cipher? Why is this the case? The histogram results of the Vigenere cipher show an increase in the frequency of the letters that were u sed in the code word â€Å"applesauce† that encrypted the document. The Caesar cipher does not show this kind of across the board increase in particular letters due to the fact that it does not work off of an encryption key of this nature, but works instead off of an alphabet shift. Q3. There is an error in the following cipher text representation of this quote; what is it? What should the correct cipher text be? SDAHFOWGRABSSRERIVBYBSCIMQTFNIVETGHBSNQCNCSDTDHBSNQCD ECNICIFCTIC The error in the following cypher text occurs in the fourth to last letter of the text. The second to last C that is listed in the above cipher text should be an O instead. The cipher text for the quote, â€Å"The difference between stupidity and genius is that genius has its limits† should read: SD AH FO WG RA BS SR ER IV BY BS CI MQ TF NI VE TG HB SN QC NC SD TD HB SN QC DE CN IC IF OT IC. Q4. Of the three ciphers discussed (Caesar, Vigenere, Playfair), what are their relative degrees of secur ity and why? Of the three ciphers discussed, the Caesar is the easiest cipher to break. This particular cipher may be found and used by anyone of any age; I can remember using it back in elementary school in order to pass notes in class. The Vigenere cipher is a bit stronger, requiring a more complex method of analysis in order to determine the proper code needed in order to unlock the â€Å"secret message.† It is the Playfair cipher, however, which shows itself to be the most secure of the three ciphers, as it removes all spacing, or generates its own spacing after every second character, making it impossible to guess the word without the need to â€Å"crack the code† first. Lab 2: Advanced Cryptography Functions Q5. For each of the following, state whether ECB or CBC would be most appropriate and give a brief explanation as to why. a. An online bank statement b. An encrypted VoIP session