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Cipher Decoding - Advanced Level: secret codes ADVANCED

Exam-focused holistic practice ★ worksheet: 20 advanced-level cipher decoding questions. Worksheet 23 of 30 targets secret codes. Build proficiency in encryption patterns, shift ciphers, substitution ciphers with detailed solutions. Ideal for advanced competitive exam preparation.

📝 Worksheet 23 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Advanced level

What you'll learn in this worksheet:
Your progress through Cipher Decoding
Worksheet 23 of 30 (76% complete)

Question 1

Using keyword cipher with keyword 'ENIGMA', decode: 'IER'
Cipher alphabet: ENIGMABCDFHJKLOPQRSTUVWXYZ
Decoding IER → CAR
keyword, substitution

Question 2

Decode the Base64 string: 'REVTRVJU'
Base64 decoding: REVTRVJU → DESERT
base64, hex, encoding

Question 3

Using Autokey cipher with initial key 'SECRET', encode: 'SISTER'
Autokey cipher: SISTER with key 'SECRET' → KMUKIK
autokey, vigenere

Question 4

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

Question 5

Using ROT13 cipher, decode: 'CIPHER'
ROT13 (shift 13): CIPHER → PVCURE
rot13, rotation

Question 6

Decode the hexadecimal string: '52414E534F4D57415245'
Hex decoding: 52414E534F4D57415245 → RANSOMWARE
base64, hex, encoding

Question 7

Using reverse cipher (writing backwards), decode: 'KWAH'
Reverse cipher: KWAH reversed is HAWK
reverse, backwards

Question 8

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

Question 9

Using Columnar Transposition cipher with key 'CIPHER', encode: 'HELLO'
Columnar Transposition with key 'CIPHER': HELLO → HOLEL
transposition, columnar

Question 10

Using reverse cipher (writing backwards), decode: 'TEKCIRC'
Reverse cipher: TEKCIRC reversed is CRICKET
reverse, backwards

Question 11

Using keyboard shift cipher (shift right on QWERTY), encode: 'MONKEY'
Keyboard shift (right): MONKEY → ZPMLRU
keyboard, qwerty

Question 12

Using Baconian cipher (5-bit binary encoding), decode: '00110 00000 01011 00000 10111 11000'
Baconian decoding: 00110 00000 01011 00000 10111 11000 → GALAXY
baconian, binary

Question 13

Using Hill cipher with key matrix [[3, 2], [5, 7]], encode: 'DESERT'
Hill cipher: DESERT → RRKOLK
hill, matrix

Question 14

Decode the hexadecimal string: '53544F52414745'
Hex decoding: 53544F52414745 → STORAGE
base64, hex, encoding

Question 15

Using Autokey cipher with initial key 'SECRET', encode: 'JUNGLE'
Autokey cipher: JUNGLE with key 'SECRET' → BYPXPX
autokey, vigenere

Question 16

Using reverse cipher (writing backwards), decode: 'LENREK'
Reverse cipher: LENREK reversed is KERNEL
reverse, backwards

Question 17

Using keyword cipher with keyword 'PRIVATE', encode: 'CHARGE'
Cipher alphabet: PRIVATEBCDFGHJKLMNOQSUWXYZ
CHARGE → IBPNEA
keyword, substitution

Question 18

Using Baconian cipher (5-bit binary encoding), decode: '01100 00100 10011 00100 01110 10001'
Baconian decoding: 01100 00100 10011 00100 01110 10001 → METEOR
baconian, binary

Question 19

Using keyboard shift cipher (shift right on QWERTY), encode: 'SECRET'
Keyboard shift (right): SECRET → DRVTRY
keyboard, qwerty

Question 20

Using Rail Fence cipher with 4 rails, encode: 'SCALA'
Rail Fence (4 rails): SCALA → SCAAL
railfence, transposition
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