Information Systems assignment4
Name:
Assignment 4
1. (20 points)
a. Using a ROT5 cipher encrypt the following plaintext. Prove your answer by showing the steps for both the encryption and decryption.
Meet at the baseball field at three oclock
Answer
b. Using a ROT3 cipher decrypt the following ciphertext. Prove your answer by showing the steps for both the encryption and decryption.
WKHF RUYH WWHL VUHG
Answer
2. (10 points)
Following are two problems using a rail fence cipher. Prove both of your answers by showing the steps involved in encryption/decryption. As part of this problem you must also show the steps involved in reversing what you are being asked for.
a. Using a rail fence cipher with key = 3 encrypt the following message:
The bird is a raven
Answer
b. Reverse the steps to decrypt your answer and explain the steps.
Answer
3. (10 points)
Rail fence cipher. Prove both of your answers by showing the steps involved in encryption/decryption. As part of this problem you must also show the steps involved in reversing what you are being asked for.
a. Using a rail fence cipher with zig zag pattern and a depth of 4 decrypt the following message:
MFEOAEOBWYUYHREIHTCT
Answer
b. Reverse the steps to encrypt your answer and explain the steps.
Answer
4. (10 points)
Decrypt the next cypher
SLCDSFWRV
by using the Vegenere Tableau and keyword SECRET
Answer
5. (10 points)
Encrypt the next message
001101010100010100110101
using XOR operation and key 01110001
Answer
6. This is a three part question. For each part the answer requires identifying an asymmetric encryption technique, hashing or both. As part of each question you need to discuss the technique to demonstrate your understanding of how the functionality (confidentiality, authenticity, integrity) is supported. You need to discuss the details of what the sender and receiver do and the key usage if applicable.
a. (10 points)
What technique is used to exchange messages between two parties ensuring confidentiality? Discuss.
Answer
b. (10 points)
What technique is used to exchange messages between two parties ensuring authenticity? Discuss.
Answer
c. (10 points)
What technique is used to exchange messages between two parties ensuring integrity? Discuss.
Answer
7. (10 points)
How can hashing be used to ensure that a file you have copied from a website has been completely and accurately copied? You should consider techniques that are in current use today for copying images and other files from servers. Provide some details with your explanation.
Answer