Information security: data encryption techniques are particularly useful for which primary purpose in operational systems?

Introduction / Context:
Encryption transforms readable data (plaintext) into an unintelligible form (ciphertext) that can only be reverted with the correct key. While encryption has several security benefits, its most prominent operational use is protecting confidentiality during transmission over untrusted networks (for example, the public internet or shared wireless links).

Given Data / Assumptions:

• We are evaluating “data encryption techniques.”
• We want the principal, most direct benefit in typical systems.
• Focus is on practical, everyday deployments (TLS, VPN, encrypted messaging).

Concept / Approach:
The clearest value of encryption is preventing eavesdroppers from understanding intercepted communications. Protocols like TLS, IPsec, and SSH encrypt data in transit, preserving confidentiality (and often authenticity). Encryption by itself does not reduce storage footprint; in fact, ciphertext can be slightly larger. Integrity can be improved when encryption is coupled with message authentication (MAC) or digital signatures, but “encryption techniques” alone imply confidentiality first and foremost, especially in data communications.

Step-by-Step Solution:

Verification / Alternative check:
Everyday examples include HTTPS for web traffic, TLS for email transport, and VPN tunnels for site-to-site links—all built around encryption to protect transit confidentiality.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming encryption solves all security objectives; confidentiality, integrity, and authenticity must each be addressed with the appropriate cryptographic mechanisms.

Final Answer:
protecting data in data communication systems