Which statement about symmetric and asymmetric encryption is true?

• A. Symmetric is slower and less scalable
• B. Asymmetric is used for bulk data encryption
• C. Symmetric is faster for bulk data; Asymmetric is used for key exchange and digital signatures
• D. Asymmetric uses the same key for both encryption and decryption

Answer: (C)

Symmetric and asymmetric encryption are designed with different strengths: speed for large data and secure key handling for identities and exchanges. Symmetric encryption uses a single shared key for both encryption and decryption, which makes its algorithms fast and efficient for handling large amounts of data. The main consideration is safely sharing that key, especially in ongoing communications.

Asymmetric encryption uses a pair of keys, a public key for encryption and a private key for decryption. The math involved is more resource-intensive, so it’s slower and less practical for bulk data. Its strength lies in key exchange and digital signatures: you can encrypt with someone’s public key to ensure confidentiality, or sign with your private key to prove ownership, with others verifying the signature using your public key.

Thus, the statement that symmetric is faster for bulk data and asymmetric is used for key exchange and digital signatures accurately reflects how these two types are typically used together in practice—symmetric for the heavy data lifting, and asymmetric for securely establishing and proving identities, often followed by symmetric encryption for the actual data.