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Cipher Decoding - Expert Level: playfair cipher EXPERT

Intensive progress check 🎯 drill: 20 expert-level cipher decoding questions. Worksheet 30 of 30 hones your playfair cipher abilities. Practice encryption patterns, shift ciphers, substitution ciphers under timed conditions. Best for expert-level students seeking challenging problems and time-bound practice.

📝 Worksheet 30 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Expert level

What you'll learn in this worksheet:
Your progress through Cipher Decoding
Worksheet 30 of 30 (100% complete)

Question 1

Using Autokey cipher with initial key 'KEY', encode: 'GIRAFFE'
Autokey cipher: GIRAFFE with key 'KEY' → QMPGNWE
autokey, vigenere

Question 2

Using Atbash cipher (A↔Z, B↔Y, C↔X...), decode: 'FLASK'
Atbash: FLASK → UOZHP
atbash, mirror

Question 3

Using ROT13 cipher, decode: 'DIFFERENTIAL'
ROT13 (shift 13): DIFFERENTIAL → QVSSRERAGVNY
rot13, rotation

Question 4

Using Columnar Transposition cipher with key 'ENIGMA', encode: 'ELEPHANT'
Columnar Transposition with key 'ENIGMA': ELEPHANT → AENPEHLT
transposition, columnar

Question 5

Using book cipher with 'Seven Wonders' [PYRAMIDS, BABYLON, ZEUS, TEMPLE, COLOSSUS, LIGHTHOUSE, MAUSOLEUM...] (6 pages, 10 words), decode positions: (pg3, w9), (pg6, w8), (pg2, w7), (pg6, w9)
Position decoding: ARTEMIS RHODES MAUSOLEUM ARTEMIS
book, position

Question 6

Using reverse cipher (writing backwards), decode: 'RETUPMOC'
Reverse cipher: RETUPMOC reversed is COMPUTER
reverse, backwards

Question 7

Using Vigenère cipher with keyword 'COMET', decode the ciphertext: 'FSOSWG'
Vigenère: With key 'COMET', FSOSWG → DECODE
vigenere, polyalphabetic

Question 8

If 'CSS' is encoded as 'GWW' using Caesar cipher, what is the shift value?
Caesar cipher: CSS → GWW. Shift = 4
caesar, shift

Question 9

Using Playfair cipher with keyword 'MONARCHY', encode: 'MOTHER'
Playfair with keyword 'MONARCHY': MOTHER → ONPDKM
playfair, digraph

Question 10

Using Vigenère cipher with keyword 'OCEAN', encode: 'BROWN'
Vigenère: BROWN with key 'OCEAN' → PTSWA
vigenere, polyalphabetic

Question 11

In Morse code, what does '-.-. --- -.. .' represent?
Morse decoding: CODE → -.-. --- -.. .
morse, dots-dashes

Question 12

Using the same Caesar cipher that encodes 'PROGRAM' as 'HJGYJSE', decode: 'KLJAFY'
Shift = 18. KLJAFY decoded (shift -18) = STRING
caesar, shift

Question 13

Using keyword cipher with keyword 'TOKEN', decode: 'KLUQS'
Cipher alphabet: TOKENABCDFGHIJLMPQRSUVWXYZ
Decoding KLUQS → COURT
keyword, substitution

Question 14

Using book cipher with 'Theory of Evolution' [NATURAL, SELECTION, SURVIVAL, FITTEST, SPECIES, ADAPT, EVOLVE...] (7 pages, 10 words), decode positions: (pg1, w10), (pg6, w8)
Position decoding: ORIGIN CHARLES
book, position

Question 15

Using Hill cipher with key matrix [[5, 8], [3, 5]], encode: 'MESSAGE'
Hill cipher: MESSAGE → OEAOWEWX
hill, matrix

Question 16

Decode the Base64 string: 'TUVNT1JZ'
Base64 decoding: TUVNT1JZ → MEMORY
base64, hex, encoding

Question 17

Using date-based cipher with date 28-04-2016 (sum of day+month+year = 20), decode: 'YHWLSJN'
Date-based cipher: Shift = 20, YHWLSJN decoded → ENCRYPT
date, calendar

Question 18

If 'PHOTOGRAPHY' is encoded as 'EWDIDVGPEWN' using Caesar cipher, what is the shift value?
Caesar cipher: PHOTOGRAPHY → EWDIDVGPEWN. Shift = 15
caesar, shift

Question 19

Using date-based cipher with date 19-10-2023 (sum of day+month+year = 24), decode: 'CLAPWNR'
Date-based cipher: Shift = 24, CLAPWNR decoded → ENCRYPT
date, calendar

Question 20

Using Columnar Transposition cipher with key 'KEY', encode: 'SYSTEM'
Columnar Transposition with key 'KEY': SYSTEM → YESTSM
transposition, columnar
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