CASE Security Architecture & Design 1 — Questions and Answers
Question 1: What is the primary purpose of the 'defense in depth' strategy in application security architecture?
- To rely on a single strong perimeter to block all attacks
- To apply multiple overlapping security layers so that failure of one control does not lead to total compromise (Correct answer)
- To encrypt all data at rest and in transit using a single algorithm
- To implement one comprehensive security policy that covers all threats
Correct answer: To apply multiple overlapping security layers so that failure of one control does not lead to total compromise
Defense in depth uses layered, overlapping controls so that bypassing one layer still leaves attackers facing additional security barriers.
Question 2: Which security design principle requires that a system's default configuration be secure without requiring additional hardening steps by the user?
- Principle of least privilege
- Economy of mechanism
- Secure by default (Correct answer)
- Separation of duties
Correct answer: Secure by default
Secure by default means the out-of-the-box configuration provides security, and less-secure options must be explicitly enabled rather than disabled.
Question 3: In security architecture, 'separation of duties' primarily mitigates which type of risk?
- SQL injection attacks targeting the database layer
- Insider threats and fraud by requiring multiple parties for sensitive operations (Correct answer)
- Denial-of-service attacks on the application
- Data loss caused by accidental deletion
Correct answer: Insider threats and fraud by requiring multiple parties for sensitive operations
Separation of duties prevents any single individual from having end-to-end control over a critical process, reducing insider threat and fraud.
Question 4: Which security architecture principle aims to reduce the number of ways an attacker can interact with or exploit a system?
- Defense in depth
- Complete mediation
- Minimize attack surface (Correct answer)
- Fail-safe defaults
Correct answer: Minimize attack surface
Minimizing the attack surface limits exposed entry points, interfaces, and functionality, giving attackers fewer opportunities to find vulnerabilities.
Question 5: In security architecture, a 'trust boundary' is best defined as:
- A firewall rule set that permits only trusted IP addresses
- A point in a system where data transitions between areas with different trust levels, requiring validation (Correct answer)
- A certificate authority that establishes trusted identities
- A security policy document listing trusted internal users
Correct answer: A point in a system where data transitions between areas with different trust levels, requiring validation
Trust boundaries mark where data moves between different trust zones, and they are key locations where input validation and access control must be enforced.
Question 6: Which network architecture pattern creates an intermediate zone between the public internet and an internal network to host publicly accessible services?
- Microservices mesh
- Model-View-Controller (MVC) pattern
- Demilitarized Zone (DMZ) (Correct answer)
- Service-oriented architecture (SOA)
Correct answer: Demilitarized Zone (DMZ)
A DMZ places internet-facing servers in an isolated zone, so a compromise of those servers does not grant direct access to the internal network.
Question 7: The 'fail-safe defaults' security design principle states that:
- Systems should automatically recover and restore functionality after any failure
- Access should be denied by default unless explicitly and specifically granted (Correct answer)
- All system failures must be logged immediately for forensic analysis
- Critical systems must maintain redundant backups at all times
Correct answer: Access should be denied by default unless explicitly and specifically granted
Fail-safe defaults mean the secure state (deny) is the default; access requires explicit permission, so ambiguous or error conditions result in denial.
CASE Security Architecture & Design 1
What is the primary purpose of the 'defense in depth' strategy in application security architecture?