E CES 212 81 Actual Questions and Correct Answers

E CES 212 81 Actual Questions and Correct Answers



Q1
Science of altering communication so that it cannot be understood without a key
Answer: Cryptography




Q2
Algorithms that simply substitute one character of cipher text for one character of plain text,
these are the most primitive algorithms
Answer: Mono-Alphabet Substitution Cipher




Q3
Every letter is simply shifted a fixed number of places to the left or to the right
Answer: Caesar Cipher




Q4
Hebrew cipher which substitutes the first letter of the alphabet for the last, and the second
letter for the second-to-last, in other words, it simply reverses the alphabet.
Answer: Atbash Cipher




Q5
The formula for any basic cipher of this type is ax+b(modM), M being the size of the alphabet,
so for example Caeser cipher would be 1x+3(mod26)
Answer: Affine Cipher




Q6
A single alphabet substitution cipher where all characters are rotated 13 characters through the
alphabet.
Answer: ROT13 Cipher