Which statement best describes the difference between symmetric and asymmetric encryption and names a typical algorithm for each?

• A. Asymmetric uses a single key; AES is typical for asymmetric encryption.
• B. Symmetric uses the same key for encryption and decryption; AES is a typical algorithm.
• C. Both symmetric and asymmetric use a single shared key.
• D. Symmetric uses a key pair; RSA or ECC are typical for asymmetric encryption.

Answer: (B)

The difference hinges on how keys are used. Symmetric encryption relies on one secret key to both encrypt and decrypt data, which makes it fast and suitable for protecting large amounts of information, but it requires a secure way to share that key between sender and receiver. AES is a typical modern algorithm for this approach. In contrast, asymmetric encryption uses a pair of keys—a public key that can be shared openly to encrypt data or verify a signature, and a private key that stays secret to decrypt data or create a signature. RSA and ECC are common examples of this type. Because the public key can be distributed without sharing a secret, asymmetric methods are often used to securely exchange a symmetric key or to create digital signatures, though they’re slower than symmetric methods and are typically used for key exchange and authentication rather than bulk data encryption. The statement that matches the best describes symmetric encryption as using the same key for encryption and decryption and identifies AES as a typical symmetric algorithm. The other descriptions mix up key usage or misname the algorithms.