Computer Security Tutorial - Encryption

Encrypt the following using the Columnar Cipher

Message: I am taking a leave of absence from school soon

Key: vacation

Ciphertext: _____________________________________________

Message: This year has been a mess of epic proportion

Key: covid

Ciphertext:______________________________________________

Decrypt the ciphertext below using Columnar Cipher

Ciphertext: ysnlr miicoe dtaas soise eofsd ibrhg rtsor eatne

Key: bachelor

Ciphertext: aareoieasielancrbdsylcrechvvir

Key: vehicle

Encrypt the message below using the Polyalphabetic Cipher

Deanslist

Faculty

Decrypt the following ciphertext using the Vigenere Tableaux

Ciphertext: ysnlr miicoe dtaas soise eofsd ibrhg rtsor eaten

Key: bachelor

RSA Calculations:

Assume p = 11, q = 13 and e = 7. Using RSA mathematical techniques, answer the following questions:

Calculate the RSA modulus n.

Determine the private key d.

Given a message M = 4, calculate the cipher value C.

Given a cipher value C = 35, calculate the original message M.

Assume p = 3, q = 11 and e = 19. Using RSA mathematical techniques, answer the following questions:

Calculate the RSA modulus n.

Determine the private key d.

Given a message M = 4, calculate the cipher value C.

Given a cipher value C = 35, calculate the original message M.