Security in Computing and IT in PDF

Running head: Security in Computing and IT
Security in Computing and IT
Name of the Student
Name of the University
Author Note

Security in Computing and IT 1
Table of Contents
Task 1:........................................................................................................................................2
Task 2:........................................................................................................................................3
Task 3:........................................................................................................................................6
Task 4:........................................................................................................................................9
References:...............................................................................................................................11

Security in Computing and IT 2
Task 1:
a)
Caesar cipher: For passing an encrypted message from one to pther person, this is the first
needed thing for both of the parties that they need to be having a key for the cipher for
encrypting the message as well as the receiver can decrypt the message. For the Caesar
cipher, the key is basically a number of characters for shifting the cipher alphabet.
Example.
Plain text: This is a secret message.
The shift: 3
Cipher text: Wklv lv d vhfuhw phvvdjh.
Transportation cipher: The decryption with the help of columnar transportation is very
much similar to the encryption. It follows a simple rule to mix up the characters the
characters of the plain text for forming the cipher text.
Example:
Let, there is a key: GERMAN
Plain text: defend the east wall of the castle
It can be written that:
G E R M A N
d e f e n d
t h e e a s
t w a l l o
f t h e c a
s t l e x x

Security in Computing and IT 3
Encryption: For encryption the columns need to be reordered alphabetically. Such that:
A E G M N R
n e d e d f
a h t e s e
l w t l o a
c t f e a h
x t s e x l
Cipher text is: nalcx ehwtt dttfs eelee dsoax feahl.
b)
For several scenarios the decryption time can more than 48 hours such as for AES decryption.
However for high end systems the time can be less such as for columner transposition the
time for decryption can be less than 60 seconds.
c)
For making the decryption process harder the user can use two combined cryptographic
methods. As that will be kind of two locks in a door but with different protocols. By
implementing two different algorithm combinely the encryption will be more strong and it
will make the decryption process harder.
d)
By understanding about the algorithms and decryption techniques properly, the process of
decryption will be faster. The most important thing for decryption is the key. If, the user will
be unaware about the keys, then there will be difficulties in decryption. However, after
known proper keys and technique the user will be able to decrypt the cipher text successfully.
Task 2:
The student ID is: 3833235