Which statement differentiates symmetric and asymmetric encryption?

Which statement differentiates symmetric and asymmetric encryption?

• A. Symmetric uses public/private key pair; Asymmetric uses same key
• B. Symmetric uses the same key for encryption/decryption; Asymmetric uses public/private key pair
• C. Symmetric is slower than Asymmetric
• D. Symmetric no keys required

Answer: (B)

The main idea is how keys are used to protect data. Symmetric encryption uses the same secret key for both encryption and decryption, so the same key must be shared between the sender and receiver. Asymmetric encryption uses a public/private key pair: the public key encrypts data, and the private key decrypts it, so the keys don’t need to be shared in the same way. This makes the differentiating statement the best answer: symmetric uses the same key for encryption and decryption, while asymmetric uses a public/private key pair. The other statements mix up the concepts. It’s not true that symmetric uses a public/private key pair, and symmetric is not slower than asymmetric—it’s typically faster for encrypting large amounts of data. Also, symmetric encryption does require keys, so claiming that no keys are required is incorrect.

The main idea is how keys are used to protect data. Symmetric encryption uses the same secret key for both encryption and decryption, so the same key must be shared between the sender and receiver. Asymmetric encryption uses a public/private key pair: the public key encrypts data, and the private key decrypts it, so the keys don’t need to be shared in the same way.

This makes the differentiating statement the best answer: symmetric uses the same key for encryption and decryption, while asymmetric uses a public/private key pair.

The other statements mix up the concepts. It’s not true that symmetric uses a public/private key pair, and symmetric is not slower than asymmetric—it’s typically faster for encrypting large amounts of data. Also, symmetric encryption does require keys, so claiming that no keys are required is incorrect.