Problem 1

The following plaintext MAJORCONTRIBUTIONWASTHEUSEOFMATH was encrypted by Hill Cipher with 2X2 key matrix and the correspondent ciphertext is KWHGLIDRQVRPFRECPQEGIJCOAEHXKWI. Find a key matrix.

Problem 2

The ciphertext is VFCKOLQOBPTEJENAFJCHBEXS
Part of plaintext is LESSPLASTIC
Find Matrix Key and decrypt the message.

Problem 3

Suppose Hill Cipher with 2X2 matrix was used to encrypt the message. Find the key matrix and decrypt the message if you know part of the plaintext MASTERCALLPROVIDES and the ciphertext ECTPXNSWVAFEJBHDKCHXCJXSNZUMANIVNJIHAZGYXIUOKC

Problem 4

The ciphertext is SELUKE
Part of plaintext is MONDAY
Find the key matrix, if possible. EXPLAIN!

Problem 5

Give an example of the plaintext/ciphertext pair for which it is impossible to find the key. You cannot use examples we already did together (cannot use MASTER and MONDAY examples of the plaintext)

Problem 6

Suppose Hill Cipher with 2X2 matrix was used to encrypt the message if you know part of the plaintext COMPLETETHE and the ciphertext ywhwbfzjohtinotiwcqidbnaqbdypqejjjcwqrvlgotpdu