Which statement describes Layered Defense in security architecture?

• A. The use of multiple controls arranged in series to provide several consecutive controls to protect an asset; also called defense in depth.
• B. A single firewall protecting access to a system.
• C. Encryption of data at rest.
• D. An incident response plan for data breach.

Answer: (A)

Layered defense means building multiple, independent controls across different layers so an attacker must overcome several barriers to reach an asset. This approach, often called defense in depth, increases resilience because weaknesses in one control are offset by others. The statement that describes several consecutive controls arranged in series to protect an asset captures this idea: you stack defenses so that one failure doesn’t immediately lead to compromise. Relying on a single firewall provides only one line of defense, which is a single point of failure. Encrypting data at rest protects confidentiality but doesn’t create multiple defensive layers by itself. An incident response plan is essential for handling breaches, but it doesn’t establish the layered protective barriers themselves.