Answered step by step
Verified Expert Solution
Link Copied!

Question

1 Approved Answer

1 . ( 8 points ) We talked about the Feistel cipher in class. Why did we at least for now restrict ourselves to discussion

1.(8 points) We talked about the Feistel cipher in class. Why did we at least for now restrict ourselves to discussion of
the feistel cipher, rather than an arbitrary reversible substitution block cipher like in Table 4.1 of our notes?
2. a)[4 points] Describe to me the difference between diffusion and confusion in regards to the design goals of a cipher.
b)[6 points] Given the DES cipher, explain the parts of the algorithm that give diffusion and the parts of the algorithm
that do confusion. While I know there is some crossover here, give a rationale for what parts more heavily focus on
diffusion or confusion or why some function might have both.
3.(10 points) a) What is the avalanche effect? Using a DES calculator found online, show an example of this. Give me
enough data in this answer so I can replicate your result, so give me any keys, data or results that you get. Of course also
tell me the calculator you used, as well as any initialization vector set.
4. a)[10 points] Encrypt the hexadecimal string C5 with a feistel cipher. Your function F should simply convert the
bitstring it is given to all 1s. Do this for two rounds.
b)[5 points] How secure is this cipher? Do you notice any pattern in what is being produced given the input?

Step by Step Solution

There are 3 Steps involved in it

Step: 1

blur-text-image

Get Instant Access to Expert-Tailored Solutions

See step-by-step solutions with expert insights and AI powered tools for academic success

Step: 2

blur-text-image

Step: 3

blur-text-image

Ace Your Homework with AI

Get the answers you need in no time with our AI-driven, step-by-step assistance

Get Started

Recommended Textbook for

Oracle9i Database Administrator Implementation And Administration

Authors: Carol McCullough-Dieter

1st Edition

0619159006, 978-0619159009

More Books

Students also viewed these Databases questions