Cisco Cyber Security Practice Exam

What type of encryption uses the same key for both encryption and decryption?

1. Symmetric

2. Asymmetric

3. Hybrid

4. Stream

The correct answer is: Symmetric

The type of encryption that uses the same key for both encryption and decryption is symmetric encryption. This approach involves using a shared secret key that is known to both the sender and the receiver. When the sender encrypts the data, they use this key, and the same key is utilized by the receiver to decrypt the data back to its original form. Symmetric encryption is efficient and typically faster than asymmetric encryption, making it ideal for encrypting large amounts of data. However, the security of symmetric encryption relies heavily on the protection of the shared key. If the key is compromised, an unauthorized party can both encrypt and decrypt messages, thus accessing confidential information. In contrast, asymmetric encryption uses a pair of keys: a public key for encryption and a private key for decryption, which means that two different keys are involved. Hybrid encryption combines both symmetric and asymmetric methods to leverage the strengths of each, often employing symmetric encryption for the actual data transfer while using asymmetric encryption for the secure exchange of the symmetric key. Stream encryption refers to a method of encrypting data where bits are encrypted one at a time but does not specifically indicate whether it is symmetric or asymmetric. Therefore, symmetric encryption fits the criteria specified in the question, emphasizing the use of the same