GIAC Foundational Cybersecurity Technologies Practice Test

What is Symmetric Encryption?

1. An encryption that uses the same key to decrypt and encrypt a message

2. An encryption that requires different keys for encryption and decryption

3. An encryption model that cannot be altered

4. An encryption that is exclusively used in government applications

The correct answer is: An encryption that uses the same key to decrypt and encrypt a message

Symmetric encryption is a method where the same key is used for both the encryption and decryption processes. This characteristic defines the essence of symmetric encryption. When a sender encrypts a message, they use this shared key to transform the plaintext into ciphertext. The intended recipient, who possesses the same key, can then decrypt the ciphertext back into its original plaintext form. The efficiency of symmetric encryption is notable because using a single key simplifies both the encryption and decryption process, making it generally faster than asymmetric encryption methods, which require a pair of keys (a public and a private key). In this context, other options are not aligned with the definition of symmetric encryption. The option discussing different keys is characteristic of asymmetric encryption. The idea of an unalterable encryption model does not specifically pertain to symmetric encryption's definition, and the notion that it is exclusively used in government applications is incorrect, as symmetric encryption is widely used in various commercial applications, including secure communications and data protection across many industries.