2.3 Encryption Cambridge IGCSE 0478

What is the main purpose of encryption?

• To protect data by making it unreadable to unauthorized users

• To increase the speed of data transmission

• To reduce the size of transmitted data

• To convert data into binary before sending

What happens if data is transmitted without encryption?

• It can be intercepted, modified, or stolen

• It will be automatically compressed

• It cannot be transmitted at all

• It will take longer to reach the recipient

Which of the following statements about symmetric encryption is correct?

• It uses the same key for both encryption and decryption

• It uses a public key for encryption and a private key for decryption

• It is less efficient than asymmetric encryption

• It does not require the sender and receiver to share a key

Which encryption method uses a public key and a private key?

• Asymmetric encryption

• Symmetric encryption

• Parity check

• Checksum

In asymmetric encryption, which key is used to decrypt the data?

• Private key

• Public key

• Symmetric key

• Checksum key

Why is asymmetric encryption more secure than symmetric encryption?

• The private key is never shared, reducing the risk of interception

• It encrypts data using fewer bits, making it faster

• It requires no keys to be exchanged between sender and receiver

• The encryption process is reversible without a key

Which of the following is an example of a symmetric encryption algorithm?

• AES (Advanced Encryption Standard)

• RSA (Rivest-Shamir-Adleman)

• SHA (Secure Hash Algorithm)

• ECC (Elliptic Curve Cryptography)

Which of the following is an example of an asymmetric encryption algorithm?

• RSA (Rivest-Shamir-Adleman)

• AES (Advanced Encryption Standard)

• RLE (Run-Length Encoding)

• DES (Data Encryption Standard)

What is the function of the public key in asymmetric encryption?

• It encrypts data that can only be decrypted by the private key

• It decrypts data sent by the sender

• It is used to check for transmission errors

• It is shared secretly between sender and receiver

Why is asymmetric encryption commonly used for secure communication over the internet?

• It allows secure data exchange without sharing a secret key

• It requires no keys to be exchanged

• It makes data transmission faster

• It is easier to implement