ReasoningAbility.com

Cipher Decoding - Beginner Level: substitution ciphers BEGINNER

Level up your cipher decoding skills with this entry level practice. 20 beginner-level problems await in Worksheet 4 of 30. Focus area: substitution ciphers. Learn substitution ciphers, transposition ciphers, key-based decoding through systematic practice. Designed for entry-level learners seeking foundational concepts and basic patterns.

📝 Worksheet 4 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Beginner level

What you'll learn in this worksheet:
Your progress through Cipher Decoding
Worksheet 4 of 30 (13% complete)

Question 1

Using Autokey cipher with initial key 'CODE', encode: 'COMET'
Autokey cipher: COMET with key 'CODE' → ECPIV
autokey, vigenere

Question 2

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

Question 3

If 'HACKER' is encoded as 'OHJRLY' using Caesar cipher, what is the shift value?
Caesar cipher: HACKER → OHJRLY. Shift = 7
caesar, shift

Question 4

Using keyword cipher with keyword 'PRIVATEKEY', encode: 'FAR'
Cipher alphabet: PRIVATEKYBCDFGHJLMNOQSUWXZ
FAR → TPM
keyword, substitution

Question 5

Using ROT13 cipher, decode: 'FOSSIL'
ROT13 (shift 13): FOSSIL → SBFFVY
rot13, rotation

Question 6

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

Question 7

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

Question 8

Using keyword cipher with keyword 'EAGLE', encode: 'BRIGHT'
Cipher alphabet: EAGLBCDFHIJKMNOPQRSTUVWXYZ
BRIGHT → ARHDFT
keyword, substitution

Question 9

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

Question 10

Using Baconian cipher (5-bit binary encoding), decode: '00100 01011 00100 01111 00111 00000 01101 10011'
Baconian decoding: 00100 01011 00100 01111 00111 00000 01101 10011 → ELEPHANT
baconian, binary

Question 11

Using reverse cipher (writing backwards), decode: 'LREP'
Reverse cipher: LREP reversed is PERL
reverse, backwards

Question 12

Using Vigenère cipher with keyword 'JUNGLE', encode: 'CRASH'
Vigenère: CRASH with key 'JUNGLE' → LLNYS
vigenere, polyalphabetic

Question 13

Using Autokey cipher with initial key 'MYSTERY', encode: 'WORLD'
Autokey cipher: WORLD with key 'MYSTERY' → IMJEH
autokey, vigenere

Question 14

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

Question 15

Using Columnar Transposition cipher with key 'MYSTERY', encode: 'ISLAND'
Columnar Transposition with key 'MYSTERY': ISLAND → NIDLAS
transposition, columnar

Question 16

Using ROT13 cipher, decode: 'REDUCTION'
ROT13 (shift 13): REDUCTION → ERQHPGVBA
rot13, rotation

Question 17

Using Vigenère cipher with keyword 'TYPESCRIPT', encode: 'VARIABLE'
Vigenère: VARIABLE with key 'TYPESCRIPT' → OYGMSDCM
vigenere, polyalphabetic

Question 18

Using Baconian cipher (5-bit binary encoding), decode: '00010 01110 01100 01111 10100 10011 00100 10001'
Baconian decoding: 00010 01110 01100 01111 10100 10011 00100 10001 → COMPUTER
baconian, binary

Question 19

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

Question 20

Using date-based cipher with date 22-10-2024 (sum of day+month+year = 2), decode: 'HTGGFQO'
Date-based cipher: Shift = 2, HTGGFQO decoded → FREEDOM
date, calendar
Previous Worksheet Next Worksheet