The use of mathematical operations to protect messages traveling between parties or stored on a computer.

• A. Cryptography
• B. Encryption
• C. Authentication
• D. Confidentiality

Answer: (A)

Cryptography is the study and practice of using mathematical techniques to protect information. It covers how to transform readable data into ciphertext and back again, enabling secure communication between parties and secure storage on a computer. This field underpins the processes that ensure confidentiality, integrity, and provenance of data through algorithms, keys, and protocols. Encryption is a core method within cryptography that actually converts plaintext to ciphertext, but cryptography also includes the broader toolkit and concepts that make secure systems possible. Authentication is about verifying identities, which is a related security goal but not the overall practice described. Confidentiality is a security objective that cryptography helps achieve, not the discipline itself.