# COMPUTER FUNDAMENTALS

## COMPUTER NETWORKS AND COMMUNICATIONS

### NETWORK SECURITY AND CYBERSECURITY

 Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Encrypt “goodday” with “say” using Vigenere cipher
 A yomtyyq B yomvdyq C yotvyyth D yrmvhyh
Explanation:

Detailed explanation-1: -To encrypt your message, you substitute each letter with another, using your key to find the intersection of the correct row and column. For example, if it messages HELLO, you encrypt the first letter H using row H. Then you use the first letter of your key to choose the correct column.

Detailed explanation-2: -The Vigenère cipher (French pronunciation: [viʒnɛːʁ]) is a method of encrypting alphabetic text by using a series of interwoven Caesar ciphers, based on the letters of a keyword. It employs a form of polyalphabetic substitution.

Detailed explanation-3: -One of the most popular cipher techniques is the vigenere cipher. It is a poly-alphabetic cipher technique which uses the vigenere table for the process of encryption of alphabets. This paper extends the vigenere table by including numerical data, so that the numbers can also be encrypted using this technique.

Detailed explanation-4: -cip := a new list. start := ASCII of ‘a’ for each l from text and k from key, do. shift := (ASCII of k)-start. pos := start +((ASCII of l)-start + shift) mod 26. insert character of pos at the end of cip. join strings of cip and return. 05-Oct-2020

There is 1 question to complete.