#!bin/python3

import numpy as np

UID = 119222119

Last_Name = 'Aaryash Raj'

First_Name = 'Sinha'

def vigenere_enc(plaintext, keyword):

# Converts the plaintext to uppercase and remove spaces

plaintext = plaintext.upper().replace(' ', '')

keyword = keyword.upper().replace(' ','')

# Repeating the keyword to match the length of the plaintext

keyword = (keyword * (len(plaintext) // len(keyword) + 1))[:len(plaintext)]

# Encrypts the plaintext using the Vigenere cipher

ciphertext = ''

for i in range(len(plaintext)):

pi = ord(plaintext[i])

ki = ord(keyword[i])

ci = ((pi + ki) % 26)

ciphertext += chr(ci+65)

return ciphertext

def vigenere_dec(ciphertext, keyword):

# Repeating the keyword to match the length of the ciphertext

keyword = (keyword * (len(ciphertext) // len(keyword) + 1))[:len(ciphertext)]

ciphertext = ciphertext.upper().replace(' ','')

keyword = keyword.upper().replace(' ', '')

# Decrypt the ciphertext using the Vigenere cipher

plaintext = ''

for i in range(len(ciphertext)):

ci = ord(ciphertext[i]) - 65

ki = ord(keyword[i]) - 65

pi = (ci - ki) % 26

plaintext += chr(pi + 65)

return plaintext

def hill_enc(M, plaintext):

# Convert the plaintext to uppercase and remove spaces

plaintext = plaintext.upper().replace(' ', '')

# Pad the plaintext with 'X' characters to make its length a multiple of 3

if len(plaintext) % 3 == 1:

plaintext += 'XX'

elif len(plaintext) % 3 == 2:

plaintext += 'X'

# Convert the plaintext to a matrix of numbers

P = []

for i in range(0, len(plaintext), 3):

P.append([ord(plaintext[i]) - 65, ord(plaintext[i+1]) - 65, ord(plaintext[i+2]) - 65])

# Encrypt the plaintext using the Hill cipher

C = []

for i in range(len(P)):

Pi = np.array(P[i]).T

Ci = np.matmul(Pi, M) % 26

C.append(Ci)

# Convert the ciphertext to a string

ciphertext = ''

for i in range(len(C)):

ciphertext += chr(C[i][0] + 65) + chr(C[i][1] + 65) + chr(C[i][2] + 65)

return ciphertext

if __name__ == "__main__":

#BANNER

print("\n\tAaryash Raj Sinha 119222119")

# Part 1: Vigenere Cipher

input_key = input("\n\n\tEnter a KEY Value: ")

input_str = input("\tEnter a String to Encrypt: ")

encstr = vigenere_enc(input_str, input_key)

print(f"\n\tVignere Cipher generated Ciphertext:\t{encstr}")

decstr = vigenere_dec(encstr, input_key)

print(f"\tVignere Cipher generated Decryptedtext:\t{decstr}")

# Part 2: Hill Cipher

input_matrix = np.array([[17, 17, 5], [21, 18, 21], [2, 2, 19]])

input_plaintext = 'Test String'

ciphertext = hill_enc(input_matrix, input_plaintext)

print(f"\n\tHill Cipher generated Ciphertext:\t{ciphertext}\n\n")