$1)$ What is a prime number?

$2)$ What are the essential ingredients of a symmetric cipher?

$3)$ What are the two basic functions used in encryption algorithms?

$4)$ How many Keys are required for two people to communicate via a cipher?

$5)$ What is the difference between block cipher and stream cipher?

$6)$ List and define types of cryptanalysis attacks based on what is known to the attacker.

$7)$ What is the difference between an unconditionally secure cipher and computationally secure cipher.

$8)$ Encrypt and decrypt $`$best Solution$`$ using Caesar cipher? Start counting from $1$ to $27$ rather than $025.$

$9)$ Encrypt and decrypt $`$best Solution$`$ using Vigen$$re cipher? Start counting from $1$ to $27$ and $27$ for space character rather than $025.$

$10)$ Solve using the Euclidean Algorithm gcd$(26,296).$ show the steps to get full grade.