ID:55732

my letter=key is (e e g c b)

.......................................................................

.......................................................................

NOTE: I think the key for task 3 is the same and it's (e e g c b).

please with some explanation.

Homework 3 Encryption/decryption with Playfair, Vigenere and simple columnar ciphers Please solve tasks below and upload to the repository on Platon website. Task 1 Encrypt the plaintext 'EXERCISE' using Playfair cipher and the key that is transformation of your ID number to the set of alphabet characters based on the rule as shown below on the exemplary case: 5 6 7 8 9 ID 56789 Letters of the alphabet = key Your ID Your letters = key E G I Answer: Task 2 Decrypt the ciphertext ZOBGWNFUQBCGUY' created by the Playfair cipher if the key is the name of deadly dangerous disease that caused the break in studying process in March 2020. One word is needed. Answer: Task 3 Decrypt the ciphertext NBSRUHATNJHGLCJCYACYGKMJLIY' created by one of polyalphabetic substitution ciphers if a key is the name of the university you are studying at. Guess the name of the cipher applying the analysis part of the programs Cryptool 1.4 or Cryptool 2.1. Answer: Task 4 Decrypt the ciphertext KIESOSNPESATMFOEETTOERTRPALFTOHSANETEMEODCAWRARN' if it was created by the simple columnar transposition cipher together with the key 'TWENTY'. Show encryption/decryption tables on the second side of page. Answer: Task 5 Encrypt the plaintext 'STAY AWAY FROM THE COUGHTING PERSON' using the simple columnar transposition cipher and the key being the number of characters of the word, that names the last digit of your ID number. For instance: 7 seven 5 characters key = 5 columns. Answer: Simple columnar transposition Cipher It is another type of cipher where the order of the alphabets in the plaintext is rearranged to create the ciphertext. The actual plaintext alphabets are not replaced. It is the cipher where the plaintext is written horizontally with a certain alphabet width. Then the ciphertext is read vertically as shown. For example, the plaintext is GOLDEN STATUE IS IN ELEVENTH CAVE" and the secret randomly chosen key is FIVE. We arrange this text horizontally in table with number of columns equal to the key value (FIVE => 5 columns). The resulting text is shown below. 5 E UZEZ 3 4 G LD N STA I N E EN H AV E OGZ HHHHHH GHH>0 C The ciphertext is obtained by reading column vertically downward from the first to the last column. The ciphertext (or better to say: ciphertext alphabet) is GNUNEAOSEENVLTILTEDASEHETIVC' and counts 28 letters. To decrypt, the receiver prepares similar table. The number of columns is equal to key number (FIVE = 5 characters = 5 columns). The number of rows is obtained by dividing number of total ciphertext alphabets (28 characters) by the key value (5) and rounding the quotient to the next integer value. So [28/57=[5,6] = 6 rows. This function is called a "roof function. The receiver then writes the received ciphertext vertically downward, from the first to the last column. To obtain the plaintext, he reads horizontally by rows from the top to the bottom