Microsoft Azure Architect Technologies (AZ-300) Practice Exam

Which type of encryption involves the use of a single secret key for both encryption and decryption?

1. Asymmetric Encryption

2. Symmetric Encryption

3. Hashing

4. Tokenization

The correct answer is: Symmetric Encryption

Symmetric encryption utilizes a single secret key for both the encryption and decryption processes. This means that the same key is employed to transform plaintext into ciphertext and then back to plaintext, making it essential for both the sender and the receiver to securely share and manage this key. This type of encryption is often faster and more efficient than asymmetric encryption, particularly for processing large amounts of data or in environments with high throughput requirements. However, its security relies heavily on the secrecy of the key; if the key is compromised, unauthorized parties can decrypt confidential information. Asymmetric encryption, on the other hand, uses a pair of keys — a public key for encryption and a private key for decryption. This adds complexity and ensures that even if the public key is widely distributed, the corresponding private key remains secure. Hashing, while often involved in data integrity verification, creates a fixed-length string from input data and cannot be reversed back to its original form, making it unsuitable for encryption needs. Tokenization replaces sensitive data with non-sensitive equivalents but doesn't provide encryption in the traditional sense. Therefore, the definition and operational mechanics of symmetric encryption distinctly highlight it as the correct answer in this context.