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WorksheetsLESSON 6 CRYPTOGRAPHY
Total questions: 14
Worksheet time: 12mins
1. Caesar Cipher Question
If the letter 'B' is encrypted using a Caesar Cipher with a left shift of 5, what will be the resulting letter?
X
Y
V
W
2. Monoalphabetic Cipher Trick
In a Monoalphabetic Cipher, if "HELLO" is encrypted as "ITSSG", what will be the decryption of "ZGGLF" using the same key?
APPLE
WORLD
GREAT
TIGER
3. Polyalphabetic Cipher Challenge
In the Vigenère Cipher, if the plaintext is "CHAT" and the keyword is "DOG", what will be the first letter of the ciphertext?
(Hint: Use A=0, B=1, C=2… Z=25 for shifts)
F
J
G
D
4. Columnar Transposition Trick
Which of the following would result in the same ciphertext when using Columnar Transposition with the same key?
Reversing the key order
Reversing the plaintext
Doubling the key length
Using the same key again for a second transposition
5. Rail Fence Cipher Challenge
If we encrypt "SECRETMESSAGE" using a 3-rail Rail Fence Cipher, which of the following is a possible ciphertext?
SCEMESERETSAG
SRTESAEMCESGE
SECEGSMRTSAE
STCERSAEEMGSE
6. Vigenère Cipher Trap
Which keyword would turn the Vigenère Cipher into a Caesar Cipher?
"ABC"
"ZZZ"
"AAA"
"XYZ"
7. Block vs. Stream Cipher Confusion
Which of the following statements is FALSE about Block and Stream Ciphers?
Block ciphers encrypt a fixed-size group of bits, while stream ciphers encrypt one bit at a time.
Stream ciphers use substitution, but block ciphers do not.
Block ciphers typically use symmetric keys.
AES is an example of a block cipher.
8. Public-Key Cryptography Mind Twister
If Alice wants to send Bob a secure message using RSA, what should she encrypt the message with?
Her own private key
Her own public key
Bob’s private key
Bob’s public key
9. Double Columnar Transposition Trap
If you apply a double Columnar Transposition using the same key both times, what will happen?
The ciphertext becomes twice as secure
The ciphertext remains unchanged
The ciphertext may become the original plaintext
The second encryption cancels the first
10. Substitution vs. Transposition Trick
Which of the following statements is incorrect?
Substitution ciphers replace letters, while transposition ciphers rearrange them.
The Caesar Cipher is an example of a transposition cipher.
The Columnar Transposition Cipher is a type of transposition cipher.
The Vigenère Cipher uses multiple substitution alphabets.
Columnar Transposition Cipher
Encrypt "HELLO WORLD" using a Columnar Transposition Cipher with the key "321" (which means you arrange the columns in the order 3→2→1). What is the ciphertext?
OLLHE DRLWO
LHEOL WLORD
LLOHE WLORD
ELHOL WDORL
Rail Fence Cipher Encryption
Encrypt "HELLO WORLD" using a 2-rail Rail Fence Cipher. What is the ciphertext?
HLOOL ELWRD
HLOEL WRLOD
HELOO LLWRD
HLOEL OWLRD
Encrypt Using a Vigenère Cipher
Encrypt the plaintext "DOG" using the keyword "KEY" in a Vigenère Cipher. What is the ciphertext?
NKQ
RIM
JPC
FQJ
Decrypt a Caesar Cipher Message
You receive the encrypted message "KHOOR", which was encrypted using a Caesar Cipher with a right shift of 3. What is the original plaintext?
HELLO
WORLD
CODED
GUESS
