QUESTION: An Internet Service Provider (ISP) is granted a block of addresses starting with 145.75.0.0/16. The ISP needs to distribute these addresses to three groups of customers as follows: (a) The first group has 128 customers; each needs 256 addresses. (b) The second group has 128 customers; each needs 64 […]
Monoalphabetic Substitution Cipher: It also known as substitution cipher. Replacement of alphabets or digits are fixed for each letter. For example: Plain text : nikhilarora Cipher text: OJLIMBSPSB In the above example, the value of ‘a’ is fixed for every time as ‘B’ and every alphabet is fixed for separate […]
Basic Terms to be used : plaintext – It is a kind of original message ciphertext – It is a type of coded message cipher – An algorithm to be performed for transforming plaintext/ciphertext. key – The information used in cipher known only to sender and receiver. encipher (encrypt) – […]
