Comprehensive and Detailed Explanation From Exact Extract:
Symmetrical (symmetric) encryption uses a single shared secret key for both encryption and decryption of data. Both the sender and the receiver must have access to the same key, and the security of the communication depends on keeping that key confidential.
Key points about symmetric encryption:
One key for both directions: The same key encrypts plaintext and decrypts ciphertext.
Fast and efficient: Often used for encrypting large amounts of data (e.g., AES).
Commonly used in secure channels after an initial key exchange has occurred.
Why the other options are incorrect:
A. Asymmetrical encryption – Uses a public key for encryption and a private key for decryption. It does not rely on a single shared secret key; rather, it uses a key pair.
B. Secure hashing – A hash function transforms data into a fixed-size value; it is one-way and does not support decryption. Hashing is not an encryption method for secure two-way communication.
C. Data masking – Obscures data (e.g., hiding digits of a credit card number) for privacy in non-production use or display; it is not an encryption method for secure communication.
Therefore, the correct answer is D. Symmetrical encryption, because it specifically involves secure communication using a shared secret key known to both parties.
[Reference:Information Technology Management study materials – Cryptography Concepts: Symmetric vs. Asymmetric Encryption., ==================================================, ]
