Question

(2) Vigenère cipher 1. Choose a password that is 5-8 letters, and write it down. 2. Write down a sentence that is about 4-6 times the length of your password. 3. Use the polyalphabetic substitution table to encode the sentence using your password. 4. Type the encrypted sentence and the password directly into your wiki page (does not need to be an attachment). 5. You'll get full credit for this portion only if I can make sense of your sentence by decrypting using your password. So you may want to give that a test run with a friend: give them your encrypted sentence and password, and see if they get it right.

Answer 1

There are two types of Encryption techniques. They are:

1) Substitution Technique

2) Transposition Technique

Polyalphabetic substitution table is one of the technique in Substitution technique.

  
Polyalphabetic Subdituation table: In polyalphabetic we are going to represent I the plain text with a brey i.e. polyalphabetic Encrypt her text - Plain text + key Cipher Tent * Roy > 25 (Cipher test) / 26 & Plain text = Cipher Text - key if Plain Trept co Plain Text & mod 26 es 26-plain Topt. EX- Key - HELLO (5- dietter) Plaine Treyt :- WHERE THERE IS A WILL THE (po-letters) (plain text is your times the cipher text) L 11 M 12 Consider :- B C D E F G H I 0 1 2 3 4 5 6 7 9 Nicanded Pith Q R S T U V W X Y 3 amtlander 16 17 18 19 20 21 22 23 24 J K 10 Z 25
  
Encryption : Key : 74 1 4 7 4 11 11 14 74 014 Plain : 22 7 4 4 197 4 17 4 8 18 0 22 8 cipher: 3 /11/15 2 180 1 15 2 18 15 22 11 22 LPclSALPcs BWLH W (Encrypted) ALPCS PWLH W Cipher text :- DLP CS SPESS 1 1 197 1815 4 18 18 SPEs is the Cipher text Adding the plain text and other text, the output is Scanned with CamScanner

Decouption : Cipher : 3 1 15|2|18101111512 113 115 122/11 pe 2 Plain. 22 7 4 17 4 19 7 4 174 8 18 o 28 text. WHERE THERE IS Awli IS A 18 |15| 4 | 18 | 18 7 4 11 1 14 11 11 1974 LL THE plain text: - WHERE THERE WILL THE text, we from cipher get the output 14 we subtract the key as plain text Scanned with CamScanner