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Cipher Decoding - Intermediate Level: playfair cipher INTERMEDIATE

Boost your speed and accuracy with this adaptive style 📈 worksheet. Worksheet 15 of 30 presents 20 intermediate-level cipher decoding problems. Focus on playfair cipher while practicing cryptography, encryption patterns, shift ciphers. Difficulty: moderate complexity with mixed patterns. Perfect for mid-level test takers.

📝 Worksheet 15 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Intermediate level

What you'll learn in this worksheet:
Your progress through Cipher Decoding
Worksheet 15 of 30 (50% complete)

Question 1

Using keyword cipher with keyword 'PERL', encode: 'FAN'
Cipher alphabet: PERLABCDFGHIJKMNOQSTUVWXYZ
FAN → BPK
keyword, substitution

Question 2

Using keyword cipher with keyword 'MYSTERY', encode: 'JUL'
Cipher alphabet: MYSTERABCDFGHIJKLNOPQUVWXZ
JUL → DQG
keyword, substitution

Question 3

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

Question 4

Using ROT13 cipher, decode: 'HEALTH'
ROT13 (shift 13): HEALTH → URNYGU
rot13, rotation

Question 5

If 'ARES' is encoded as 'GXKY' using Caesar cipher, what is the shift value?
Caesar cipher: ARES → GXKY. Shift = 6
caesar, shift

Question 6

Decode the Base64 string: 'TElCRVJUWQ=='
Base64 decoding: TElCRVJUWQ== → LIBERTY
base64, hex, encoding

Question 7

Using Baconian cipher (5-bit binary encoding), decode: '01100 00100 10010 10010 00000 00110 00100'
Baconian decoding: 01100 00100 10010 10010 00000 00110 00100 → MESSAGE
baconian, binary

Question 8

Using ROT13 cipher, decode: 'DIRECTORY'
ROT13 (shift 13): DIRECTORY → QVERPGBEL
rot13, rotation

Question 9

Using Playfair cipher with keyword 'PLAYFAIR', encode: 'CHASE'
Playfair with keyword 'PLAYFAIR': CHASE → BKYQKU
playfair, digraph

Question 10

Using Vigenère cipher with keyword 'ENCRYPTION', encode: 'SPACESHIP'
Vigenère: SPACESHIP with key 'ENCRYPTION' → WCCTCHAQD
vigenere, polyalphabetic

Question 11

Using keyword cipher with keyword 'METEOR', decode: 'APRROKI'
Cipher alphabet: METORABCDFGHIJKLNPQSUVWXYZ
Decoding APRROKI → FREEDOM
keyword, substitution

Question 12

Using Autokey cipher with initial key 'CODE', encode: 'COMPUTER'
Autokey cipher: COMPUTER with key 'CODE' → ECPTWHQG
autokey, vigenere

Question 13

Decode the hexadecimal string: '41555448454E5449434154494F4E'
Hex decoding: 41555448454E5449434154494F4E → AUTHENTICATION
base64, hex, encoding

Question 14

Using Rail Fence cipher with 5 rails, encode: 'STORAGE'
Rail Fence (5 rails): STORAGE → STOERGA
railfence, transposition

Question 15

Using Baconian cipher (5-bit binary encoding), decode: '01100 00100 01100 01110 10001 11000'
Baconian decoding: 01100 00100 01100 01110 10001 11000 → MEMORY
baconian, binary

Question 16

Using keyword cipher with keyword 'AUTHORIZATION', encode: 'FATHER'
Cipher alphabet: AUTHORIZNBCDEFGJKLMPQSVWXY
FATHER → RAPZOL
keyword, substitution

Question 17

Using book cipher with 'May The Force Be With You' [MAY, THE, FORCE, BE, WITH, YOU, JEDI...] (5 pages, 10 words), decode positions: (pg1, w4), (pg3, w8), (pg3, w3)
Position decoding: BE SITH FORCE
book, position

Question 18

If 'CODE' is encoded as 'XJYZ' using Caesar cipher, what is the shift value?
Caesar cipher: CODE → XJYZ. Shift = 21
caesar, shift

Question 19

Using Baconian cipher (5-bit binary encoding), decode: '00111 00100 01011 01011 01110'
Baconian decoding: 00111 00100 01011 01011 01110 → HELLO
baconian, binary

Question 20

Decode the Base64 string: 'RklSRVdBTEw='
Base64 decoding: RklSRVdBTEw= → FIREWALL
base64, hex, encoding
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