In symmetric encryption, how many keys are used to encrypt and decrypt data?

Correct option is C

In symmetric encryption, the same single key is used for both encrypting and decrypting the data. This means that both the sender and the receiver must share the same key, which they use to perform encryption and decryption operations. The security of symmetric encryption relies on the secrecy of this shared key.
Important Key Points:
1. Single Key: In symmetric encryption, only one key is used for both encryption and decryption.
2. Efficiency: Symmetric encryption is generally faster and more efficient compared to asymmetric encryption because it uses the same key for both processes.
3. Key Security: The key must be kept secret between the sender and receiver, as anyone with access to the key can decrypt the data.
Knowledge Booster:
· Three Keys: Three keys are not used in symmetric encryption. The term "three keys" might be confused with certain hybrid encryption systems that involve multiple encryption algorithms.
· Two Keys: Two keys are used in asymmetric encryption, not symmetric encryption.
· No Key: This is incorrect, as symmetric encryption relies on the use of a secret key for both encryption and decryption.