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Cipher Decoding - Beginner Level: key-based decoding BEGINNER

Master cipher decoding concepts through this speed drill practice set. Worksheet 6 of 30 contains 20 beginner-level problems. Deep dive into key-based decoding while learning key-based decoding, cipher algorithms, secret codes. Recommended for entry-level learners aiming for foundational concepts and basic patterns.

📝 Worksheet 6 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Beginner level

What you'll learn in this worksheet:
Your progress through Cipher Decoding
Worksheet 6 of 30 (20% complete)

Question 1

Using ROT13 cipher, decode: 'HABITAT'
ROT13 (shift 13): HABITAT → UNOVGNG
rot13, rotation

Question 2

Using book cipher with 'World Capitals' [LONDON, PARIS, TOKYO, DELHI, BEIJING, MOSCOW, CAIRO...] (5 pages, 10 words), decode positions: (pg2, w4), (pg5, w10)
Position decoding: DELHI CANBERRA
book, position

Question 3

Using date-based cipher with date 25-01-2008 (sum of day+month+year = 6), decode: 'IUSVAZKX'
Date-based cipher: Shift = 6, IUSVAZKX decoded → COMPUTER
date, calendar

Question 4

Using Autokey cipher with initial key 'MYSTERY', encode: 'GIRAFFE'
Autokey cipher: GIRAFFE with key 'MYSTERY' → SGJTJWC
autokey, vigenere

Question 5

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

Question 6

Using book cipher with 'Pythagorean Theorem' [SQUARED, PLUS, EQUALS, HYPOTENUSE, TRIANGLE, RIGHT, ANGLE...] (4 pages, 10 words), decode positions: (pg1, w1), (pg2, w1)
Position decoding: SQUARED SQUARED
book, position

Question 7

Using Hill cipher with key matrix [[7, 8], [11, 13]], encode: 'FREEDOM'
Hill cipher: FREEDOM → PQISDHIP
hill, matrix

Question 8

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

Question 9

Using Autokey cipher with initial key 'ENIGMA', encode: 'IMPORTANT'
Autokey cipher: IMPORTANT with key 'ENIGMA' → MZXUDTIZI
autokey, vigenere

Question 10

Using the same Caesar cipher that encodes 'ELEPHANT' as 'YFYJBUHN', decode: 'JCTTU'
Shift = 20. JCTTU decoded (shift -20) = PIZZA
caesar, shift

Question 11

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

Question 12

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

Question 13

Using Columnar Transposition cipher with key 'MYSTERY', encode: 'ANTIVIRUS'
Columnar Transposition with key 'MYSTERY': ANTIVIRUS → VAUITINSR
transposition, columnar

Question 14

Using ROT13 cipher, decode: 'PEACE'
ROT13 (shift 13): PEACE → CRNPR
rot13, rotation

Question 15

Using Columnar Transposition cipher with key 'CIPHER', encode: 'WORLD'
Columnar Transposition with key 'CIPHER': WORLD → WDLOR
transposition, columnar

Question 16

Using date-based cipher with date 28-03-2018 (sum of day+month+year = 21), decode: 'KTOCJI'
Date-based cipher: Shift = 21, KTOCJI decoded → PYTHON
date, calendar

Question 17

Using date-based cipher with date 26-07-2025 (sum of day+month+year = 4), decode: 'WSJXAEVI'
Date-based cipher: Shift = 4, WSJXAEVI decoded → SOFTWARE
date, calendar

Question 18

If 'BINARY' is encoded as 'CJOBSZ' using Caesar cipher, what is the shift value?
Caesar cipher: BINARY → CJOBSZ. Shift = 1
caesar, shift

Question 19

Using Columnar Transposition cipher with key 'MYSTERY', encode: 'MESSAGE'
Columnar Transposition with key 'MYSTERY': MESSAGE → AMGSSEE
transposition, columnar

Question 20

Using Playfair cipher with keyword 'LOCK', encode: 'CRYPTO'
Playfair with keyword 'LOCK': CRYPTO → OSZNRK
playfair, digraph
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