SE Security Architecture and Design 1 — Questions and Answers
Question 1: What is the core principle of Zero Trust Architecture?
- Trust all internal network traffic by default
- Never trust, always verify — authenticate and authorize every request regardless of network location (Correct answer)
- Block all external traffic at the perimeter
- Trust users after initial login for the rest of the session
Correct answer: Never trust, always verify — authenticate and authorize every request regardless of network location
Zero Trust assumes breach and requires continuous verification of every user, device, and request regardless of whether it originates inside or outside the network.
Question 2: Which security design principle advocates building multiple layers of defense so that if one layer fails, others continue to protect?
- Least privilege
- Defense in depth (Correct answer)
- Fail secure
- Economy of mechanism
Correct answer: Defense in depth
Defense in depth layers technical, administrative, and physical controls so an attacker must bypass multiple independent defenses to succeed.
Question 3: What does 'fail secure' (fail closed) mean in security design?
- Systems continue operating during failures to maintain availability
- When a system fails, it defaults to a secure state that denies access rather than granting it (Correct answer)
- Logs are preserved even after system failure
- Automatic patching occurs on failure
Correct answer: When a system fails, it defaults to a secure state that denies access rather than granting it
Fail secure means a system in an error or failure state denies access by default, preventing security bypasses through induced failures.
Question 4: Which security design principle recommends that security mechanisms should be as simple as possible to facilitate verification and reduce attack surface?
- Open design
- Economy of mechanism (Correct answer)
- Complete mediation
- Separation of privilege
Correct answer: Economy of mechanism
Economy of mechanism (simplicity) reduces the likelihood of design and implementation flaws by keeping security mechanisms small and understandable.
Question 5: What is threat modeling and when should it ideally be performed?
- Testing production systems for vulnerabilities; after deployment
- A structured process to identify, quantify, and address security threats; ideally during the design phase (Correct answer)
- Writing security policies; during audits
- Scanning for known CVEs; during patching cycles
Correct answer: A structured process to identify, quantify, and address security threats; ideally during the design phase
Threat modeling systematically identifies threats, attack vectors, and mitigations early in the design phase when changes are least costly.
Question 6: Which architecture pattern places all security enforcement at a single point through which all access must pass?
- Distributed security controls
- Choke point / complete mediation (Correct answer)
- Decentralized identity
- Microservices mesh
Correct answer: Choke point / complete mediation
Complete mediation ensures every access request is checked through a central enforcement point, preventing policy bypass through alternate paths.
SE Security Architecture and Design 1
What is the core principle of Zero Trust Architecture?