Hardware Security

What is the idea of "defense in depth," emphasized in hardware and software security?

  1. AChoosing only the single strongest countermeasure and omitting the rest
  2. BLayering several different countermeasures so the whole is not breached even if one fails
  3. CDoing nothing and thinking only after an attack
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Answer: B. Layering several different countermeasures so the whole is not breached even if one fails

Every countermeasure may have weaknesses not yet discovered. Defense in depth layers different kinds of protection, such as secure boot, memory protection, TEEs, encryption, side-channel countermeasures and physical tamper resistance, so that when one is breached the next layer still holds. The cost and effort for an attacker to defeat every layer at once is what makes the whole secure.

  • A. If that one fails, everything fails.
  • B. Correct. It assumes no single measure is perfect.
  • C. Advance countermeasures are needed.
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More Hardware Security questions

  1. When manufacturing many devices, why give each device its own key instead of the same key in all of them?
  2. When a CPU hardware vulnerability is discovered, which is one countermeasure applied to CPUs already shipped?
  3. Which best describes the problems addressed by hardware security?
  4. Which describes a side-channel attack?
  5. Which correctly pairs the principle behind timing attacks with a typical countermeasure?