Ch15 : Encryption

Multiple Choice

What is the difference between asymmetric and symmetric encryption?

• Asymmetric uses two keys, symmetric uses one key

• Asymmetric is faster than symmetric

• Symmetric is more secure than asymmetric

• Asymmetric is used for HTTPS connections

Multiple Choice

What must a user need to decrypt a file?

• Coin

• Key

• Token

• Graph

Multiple Choice

What is the purpose of data encryption?

• To speed up data transfer

• To make data unreadable to unauthorized users

• To reduce the amount of data storage needed

• To make data easier to read

Multiple Choice

"______ encryption is a method of encryption involving one key for both encryption and decryption."

• Private Key

• Symmetric

• Asymmetric

• Public Key

Multiple Choice

Which process involves transforming ciphertext into plaintext using a key

• encryption
• scrambling
• decryption
• encoding

Drag and Drop

There are 2 main types of data encryption. ​

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encryption is where data is encrypted and decrypted using the same ​

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. ​

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encryption uses 2 different keys, a ​

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key for encrypting data that anyone can know and a ​

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key used for decryption that must be kept private!

Drag these tiles and drop them in the correct blank above

symmetric

key

asymmetric

public

private

password

authentication

hacker

Multiple Choice

Plan a strategy to decode a Pigpen Cipher message without a key.

• Use frequency analysis to determine common symbols.

• Randomly guess the letters.

• Use a computer program to brute force the message.

• Look for patterns and common words in the symbols.

Multiple Choice

What is encryption?

• A person who tricks you into giving your password

• converting information or data into a code to prevent unauthorized access.

• To upload your personal data to the cloud

• When there is a security breach in your data

Multiple Select

What does Encryption Mean? (Select two answers)

• That data can no longer be read without the key

• That data is secure

• That data has been lost

• That data is changed

Match

Match the following

• The same key is used to encrypt and decrypt the message.

• Different keys are used to encrypt and decrypt the message.

• Key shared with everybody used to encrypt a message.

• Key that can only be decrypted by a computer with access.

Symmetric

Asymmetric

Public Key

Private Key

• Symmetric

• Asymmetric

• Public Key

• Private Key

Multiple Choice

Compare the Pigpen Cipher to the Caesar Cipher. Which statement is true?

• Both ciphers use geometric symbols.

• The Pigpen Cipher is more secure than the Caesar Cipher.

• The Caesar Cipher shifts letters, while the Pigpen Cipher uses symbols.

• Both ciphers were used by the Freemasons.

Multiple Choice

In a Caesar cipher with a key of –3, what happens to the letters of the alphabet?

• a) They are shifted three places to the right

• b) They are replaced with numbers

• c) They are shifted three places to the left

• d) They are arranged in random order

Multiple Choice

To decrypt a Caesar cipher, the letters are shifted in the same direction as encryption.

• True

• False

Multiple Choice

What is the purpose of the Caesar cipher algorithm?

• To encrypt messages

• To decrypt messages

• To both encrypt and decrypt messages

• To analyze strings

Multiple Choice

What is the first step in the flowchart for setting out a Caesar cipher?

• Input 'e' for encryption

• Input 'd' for decryption

• Input shift to be used

• Input message to be encrypted or decrypted

Multiple Choice

What are the sub-problems that your program needs to address when checking user input?

• Checking if the input is empty

• Traversing the string

• Handling upper and lower case letters

• Leaving characters as they are

Multiple Choice

What will happen if the key is +3 and the letter to be encoded is 'X'?

• It will encrypt to 'A'

• It will encrypt to 'B'

• It will encrypt to 'C'

• It will encrypt to 'D'

Multiple Choice

What are the steps involved in using functions for structured programming?

• Ask the user for the key

• Ask the user for the message

• Carry out the encryption or decryption

• Ask the user if they want to encrypt or decrypt

Multiple Choice

What values do the functions return that are used by the main program?

• Get method

• Get key

• Get message

• Decrypt message

Multiple Choice

______________ is/are Programs designed by dividing problems into smaller, logical problems to make them easier to execute. 

• Structured Programming
• Computer
• Data
• Programming

Multiple Choice

Creating a sequence of instructions to enable the computer to do something.

• Structured Programming
• Computer
• Data
• Programming

Multiple Choice

What does the variable 'run' control in the given code?

• The method of encryption

• The loop execution

• The key for encryption

• The message to display

Multiple Choice

What is the Vigenère cipher based on?

• Polyalphabetic substitution

• Single alphabet substitution

• Transposition

• None of the above

Multiple Choice

What is the Vigenère cipher used for?

• Encrypting messages

• Decrypting messages

• Both encrypting and decrypting messages

• None of the above

Multiple Choice

What is the term used to refer to the original message before encryption?

• Ciphertext

• Plaintext

• Keyword

• Encryption

Multiple Choice

What is the purpose of the keyword in developing a keystream?

• To encrypt the plaintext

• To generate the keystream

• To decode the message

• To create a cipher

Multiple Choice

What is the ciphertext for the plaintext 'this is a message' using the keystream 'code'?

• VVLW KW D QGGVEIS

• VVLW KW D QGGVEIS

• VVLW KW D QGGVEIS

• VVLW KW D QGGVEIS

Multiple Choice

What is the process of changing plain text into a cipher for the purpose of security or privacy?

• Denial of Service

• Encryption

• Endpoint Protection Platform

• Digital Signature

Multiple Choice

What is the encrypted ciphertext when using the rail fence cipher with a key of 4?

• taghsmaeiiesss

• tieghsssmsaeias

• taghsmaeisss

• tieghsssmseaias

Multiple Choice

What is the key used to encrypt the message in the rail fence cipher?

• 2

• 3

• 4

• 5

Multiple Choice

What are the stages of filling in the letters of the ciphertext to decrypt the message?

• Stage 1

• Stage 2

• Stage 3

• Stage 4

Multiple Choice

What type of key can be freely shared with anyone so that they can encrypt a message?

• Personal key
• Private key
• Free key
• Public key

Multiple Choice

If the same key is used to encrypt and decrypt a message, this is known as? 

• Symmetric encryption
• Encryption doesn't exist!
• Asymmetric encryption
• Same-key encryption

Multiple Choice

Explain the difference between encryption and decryption.

• Encryption converts plaintext to ciphertext, while decryption converts ciphertext to plaintext.

• Encryption is used for compressing data, while decryption is used for decompressing data.

• Encryption converts ciphertext to plaintext, while decryption converts plaintext to ciphertext.

• Encryption and decryption are the same process.

Poll

How confident do you feel about this topic now?

• Very confident
• Somewhat confident
• Not confident