About this Study Set
This study set covers Cryptography through
20 practice questions.
This quiz tests basic knowledge of cryptography, focusing on simple ciphers and their historical uses, suitable for elementary school students. Every question includes the correct answer so you can learn as you go — pick any format above to get started.
Questions & Answers
Browse all 20 questions from the
Cracking the Code: Elementary Cryptography study set below.
Each question shows the correct answer — select a study format above to practice interactively.
1
What is a simple way to swap letters in a message to make it secret, like shifting them down the alphabet?
-
A
Encryption
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B
Decryption
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C
A Caesar Cipher
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D
A Password
2
Who was Julius Caesar, a famous historical figure known for using a simple letter-shifting code?
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A
A famous artist
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B
A Roman general and leader
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C
A scientist who invented the alphabet
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D
A storyteller
3
If you use a Caesar cipher to shift letters by 3, what would 'A' become?
4
What do we call the secret message that has been changed to hide its meaning?
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A
Plaintext
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B
Ciphertext
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C
Algorithm
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D
Key
5
In cryptography, what is the original, readable message called before it's made secret?
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A
Ciphertext
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B
Plaintext
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C
Scrambled text
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D
Code
6
What is the special instruction or secret word needed to change a message into a secret code or back again?
-
A
A cipher
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B
A key
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C
A password
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D
An emoji
7
What is the process of turning a readable message into a secret code called?
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A
Decryption
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B
Encoding
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C
Encryption
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D
Decoding
8
What is the opposite process of making a secret code into a readable message?
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A
Encryption
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B
Encoding
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C
Decryption
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D
Locking
9
What historical tool or machine was used to help create and decipher codes more quickly, especially during World War II?
-
A
A computer
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B
A typewriter
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C
The Enigma machine
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D
A telegraph
10
Which of these is a famous example of a simple substitution cipher where each letter is replaced by another fixed letter?
-
A
Password protection
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B
A Caesar Cipher
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C
A QR code
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D
A barcode
11
Why do people use cryptography?
-
A
To make messages longer
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B
To keep messages private and secure
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C
To make messages harder to read
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D
To send messages faster
12
What is a code or method used to scramble a message called?
-
A
Plaintext
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B
Key
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C
Algorithm
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D
Cipher
13
If a secret message is written in ciphertext, what do you need to read it?
-
A
A special decoder ring
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B
A magnifying glass
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C
The correct key and method
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D
A secret handshake
14
Historically, spies and armies used codes to:
-
A
Send invitations to parties
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B
Share recipes
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C
Communicate secret plans
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D
Write poems
15
Which of these is NOT a type of code or cipher?
-
A
Caesar Cipher
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B
Morse Code
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C
A Phone Number
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D
Enigma Machine Code
16
What does 'decipher' mean in the context of codes?
-
A
To create a new code
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B
To make a code more complicated
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C
To turn a secret code back into a readable message
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D
To send a message in code
17
Which famous scientist is credited with developing one of the earliest known methods of cryptography, used by his army?
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A
Isaac Newton
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B
Albert Einstein
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C
Julius Caesar
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D
Marie Curie
18
What is the simplest form of cryptography, where you might just swap letters or words out for other letters or words?
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A
Complex algorithms
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B
Simple substitution
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C
Quantum encryption
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D
Biometric security
19
What is a common, everyday example of something that uses cryptography to keep information safe?
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A
A library book
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B
A computer password
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C
A piece of chalk
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D
A drawing
20
If you are 'encrypting' a message, what are you doing?
-
A
Making it easier to read
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B
Making it secret
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C
Sending it to everyone
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D
Translating it to another language
