Security architecture and design are core domains in the CompTIA Security+ exam (SY0-701). To protect modern IT environments, professionals must understand principles of defense-in-depth, system hardening, secure network design, and cloud security.
This post contains 50 Security+ MCQs with detailed explanations, covering:
- Defense-in-depth strategies and layered security
- Enterprise and cloud architecture models
- Zero Trust security principles
- System hardening and secure configurations
- Network segmentation and secure protocols
If you’re preparing for Security+ in the USA, UK, Canada, Australia, or Europe, this set will help you master architecture concepts for exam and real-world success.
🔐 CompTIA Security+ Security Architecture & Design MCQs (51–100)
51. Which principle best describes the concept of “defense-in-depth”?
A) Relying on a single security device for protection
B) Using multiple layers of security controls across systems
C) Limiting users to one authentication factor
D) Deploying only firewalls at the perimeter
✅ Answer: B) Using multiple layers of security controls across systems
Explanation: Defense-in-depth applies layered security, combining technical, administrative, and physical controls. Even if one layer fails, others continue to protect the system.
52. What is the primary goal of Zero Trust architecture?
A) Allow all internal users unrestricted access
B) Assume everything inside the network is secure
C) Verify every request regardless of source or location
D) Eliminate the need for authentication
✅ Answer: C) Verify every request regardless of source or location
Explanation: Zero Trust works on the principle of “never trust, always verify”, requiring authentication, authorization, and continuous monitoring of all users and devices.
53. Which of the following is a benefit of network segmentation?
A) Simplifies network management
B) Limits lateral movement in case of compromise
C) Removes the need for encryption
D) Replaces firewalls and IDS
✅ Answer: B) Limits lateral movement in case of compromise
Explanation: Segmentation divides networks into smaller zones, restricting attackers from moving freely across systems. It is vital for PCI-DSS compliance and defense against ransomware.
54. Which secure design principle reduces the attack surface by allowing only necessary functions?
A) Least functionality
B) Least privilege
C) Separation of duties
D) Redundancy
✅ Answer: A) Least functionality
Explanation: Least functionality ensures only essential services and ports are enabled, minimizing potential vulnerabilities.
55. In a cloud environment, what does shared responsibility model mean?
A) Cloud provider handles all security controls
B) Customer handles all security controls
C) Provider secures infrastructure, customer secures data and apps
D) No party is responsible for security
✅ Answer: C) Provider secures infrastructure, customer secures data and apps
Explanation: In the cloud shared responsibility model, providers secure the infrastructure, while customers are responsible for data, identity, and application security.
56. What is the main advantage of redundancy in system design?
A) Reduces hardware costs
B) Prevents malware infections
C) Improves system availability during failures
D) Eliminates the need for backups
✅ Answer: C) Improves system availability during failures
Explanation: Redundancy (RAID, failover systems, multiple ISPs) ensures business continuity and prevents downtime from single points of failure.
57. Which architectural design uses multiple layers of firewalls to protect sensitive networks?
A) Honeypot network
B) Bastion host
C) Demilitarized Zone (DMZ)
D) Screened subnet
✅ Answer: D) Screened subnet
Explanation: A screened subnet (DMZ architecture) places public-facing servers between two firewalls, reducing risks of direct access to internal systems.
58. Which protocol ensures secure remote administration?
A) Telnet
B) SSH
C) FTP
D) SNMPv1
✅ Answer: B) SSH
Explanation: SSH (Secure Shell) encrypts remote administrative sessions, unlike Telnet, which transmits data in plaintext.
59. Which access control method assigns permissions based on job role?
A) Mandatory Access Control (MAC)
B) Role-Based Access Control (RBAC)
C) Discretionary Access Control (DAC)
D) Attribute-Based Access Control (ABAC)
✅ Answer: B) Role-Based Access Control (RBAC)
Explanation: RBAC provides access based on job functions, enforcing least privilege and separation of duties.
60. Which concept ensures critical systems continue operating even if one fails?
A) Load balancing
B) Fault tolerance
C) Hardening
D) Obfuscation
✅ Answer: B) Fault tolerance
Explanation: Fault tolerance uses redundancy and failover mechanisms to maintain availability during hardware/software failures.
Q61. What is the main purpose of covert channels in computer security?
A. To strengthen firewall rules
B. To allow attackers to bypass security policies secretly
C. To securely encrypt wireless traffic
D. To provide redundancy in system design
✅ Answer: B. To allow attackers to bypass security policies secretly
Explanation: Covert channels are unauthorized communication paths that can transfer information in violation of the system’s security policy.
Q62. Which type of covert channel uses system resources (like CPU or file locks) to leak information?
A. Covert timing channel
B. Covert storage channel
C. Data hiding
D. Steganography
✅ Answer: B. Covert storage channel
Explanation: Covert storage channels use shared system storage (files, buffers) to communicate secretly, bypassing security.
Q63. Which type of covert channel relies on manipulating system timings?
A. Covert timing channel
B. Covert storage channel
C. Side-channel attack
D. Trojan horse
✅ Answer: A. Covert timing channel
Explanation: In covert timing channels, attackers manipulate system timings (e.g., response times) to leak data covertly.
Q64. Which access control model is primarily used to enforce confidentiality with security labels?
A. Discretionary Access Control (DAC)
B. Mandatory Access Control (MAC)
C. Role-Based Access Control (RBAC)
D. Attribute-Based Access Control (ABAC)
✅ Answer: B. Mandatory Access Control (MAC)
Explanation: MAC uses labels (e.g., Top Secret, Confidential) to enforce confidentiality policies strictly, with decisions made by the system, not users.
Q65. In the Bell-LaPadula model, the simple security property states:
A. “No read down”
B. “No write down”
C. “No read up”
D. “No write up”
✅ Answer: C. “No read up”
Explanation: Bell-LaPadula (focused on confidentiality) prevents subjects from reading data at a higher classification level (no read up).
Q66. In the Bell-LaPadula model, the star property (“* property”) states:
A. “No write up”
B. “No write down”
C. “No read down”
D. “No execute up”
✅ Answer: B. “No write down”
Explanation: The star property prevents data from being written to a lower classification level, ensuring higher-level data doesn’t leak downward.
Q67. Which access control model focuses on integrity rather than confidentiality?
A. Bell-LaPadula
B. Biba
C. Clark-Wilson
D. Brewer-Nash
✅ Answer: B. Biba
Explanation: The Biba model is designed to protect integrity by enforcing rules like “no write up” and “no read down.”
Q68. In the Biba model, the simple integrity axiom states:
A. “No write up”
B. “No read down”
C. “No read up”
D. “No write down”
✅ Answer: B. “No read down”
Explanation: The simple integrity axiom ensures subjects cannot read data at lower integrity levels, avoiding corruption from less trustworthy sources.
Q69. In the Biba model, the integrity star property states:
A. “No write up”
B. “No write down”
C. “No execute up”
D. “No modify down”
✅ Answer: A. “No write up”
Explanation: This prevents less trustworthy subjects from writing to higher integrity levels, thereby preserving data reliability.
Q70. The Clark-Wilson integrity model introduces which key concept?
A. Covert timing channels
B. Security labels and clearances
C. Well-formed transactions and separation of duties
D. Trusted paths for user communication
✅ Answer: C. Well-formed transactions and separation of duties
Explanation: The Clark-Wilson model ensures data integrity by requiring all modifications to be done through controlled transactions, with enforcement of separation of duties.
Q71. Which security model is also known as the Chinese Wall model?
A. Clark-Wilson
B. Brewer-Nash
C. Bell-LaPadula
D. Biba
✅ Answer: B. Brewer-Nash
Explanation: The Brewer-Nash (Chinese Wall) model prevents conflicts of interest by restricting access based on previously accessed data sets.
Q72. The Brewer-Nash model is primarily designed to protect against:
A. Insider threats
B. Data integrity corruption
C. Conflict of interest situations
D. Malware infections
✅ Answer: C. Conflict of interest situations
Explanation: It ensures that a subject cannot access conflicting sets of information (e.g., an analyst working with two competing companies).
Q73. Which security model is specifically designed for commercial integrity requirements?
A. Biba
B. Clark-Wilson
C. Bell-LaPadula
D. Brewer-Nash
✅ Answer: B. Clark-Wilson
Explanation: Clark-Wilson emphasizes integrity using well-formed transactions and separation of duties, common in commercial systems.
Q74. Which term refers to the highest level of security domain in a computer system?
A. User Mode
B. Kernel Mode
C. Ring 0
D. Ring 3
✅ Answer: C. Ring 0
Explanation: In ring-based architectures, Ring 0 (kernel mode) has the highest privilege, while Ring 3 (user mode) has the least.
Q75. Which of the following is NOT a requirement of the reference monitor concept?
A. Completeness
B. Isolation
C. Verifiability
D. Flexibility
✅ Answer: D. Flexibility
Explanation: Reference monitors must be complete, isolated, and verifiable. Flexibility is not one of its formal requirements.
Q76. Which model uses information flow control to ensure confidentiality?
A. Bell-LaPadula
B. Biba
C. Clark-Wilson
D. Brewer-Nash
✅ Answer: A. Bell-LaPadula
Explanation: Bell-LaPadula enforces confidentiality by controlling how information flows between subjects and objects.
Q77. Which of the following is an example of security domain separation?
A. User accounts and admin accounts being isolated
B. Two firewalls working together
C. Running antivirus scans on all servers
D. Encrypting database backups
✅ Answer: A. User accounts and admin accounts being isolated
Explanation: Domain separation ensures that actions and privileges are restricted to their designated areas, reducing risk.
Q78. What is the least privilege principle?
A. Allowing full access to trusted users only
B. Restricting subjects to the minimum level of access necessary
C. Allowing only administrators to use the system
D. Restricting access to physical data centers
✅ Answer: B. Restricting subjects to the minimum level of access necessary
Explanation: Least privilege ensures users and processes get only the permissions required to perform their tasks.
Q79. What is the main security concern with open design?
A. Attackers cannot understand the system
B. The system relies on secrecy for protection
C. Security should not depend on system secrecy
D. Only closed systems are secure
✅ Answer: C. Security should not depend on system secrecy
Explanation: Open design means security mechanisms should remain secure even if the design is public knowledge.
Q80. Which model enforces confidentiality by preventing a subject at a lower level from writing to a higher level?
A. Bell-LaPadula
B. Biba
C. Clark-Wilson
D. Brewer-Nash
✅ Answer: A. Bell-LaPadula
Explanation: Bell-LaPadula enforces “no read up, no write down,” protecting confidentiality.
Q81. Which security model enforces no write up, no read down?
A. Bell-LaPadula
B. Biba
C. Clark-Wilson
D. Brewer-Nash
✅ Answer: B. Biba
Explanation: Biba protects data integrity with “no write up, no read down” rules.
Q82. Which term refers to the process of proving that a system design satisfies security requirements?
A. Validation
B. Verification
C. Accreditation
D. Certification
✅ Answer: B. Verification
Explanation: Verification ensures that a system is correctly built according to its security specifications.
Q83. Which process ensures that a system operates according to user needs and expectations?
A. Validation
B. Verification
C. Certification
D. Accreditation
✅ Answer: A. Validation
Explanation: Validation ensures the system does what the users require and meets operational needs.
Q84. Certification and accreditation (C&A) are processes that:
A. Apply only to physical security
B. Ensure systems are evaluated and approved for use
C. Apply only to operating systems
D. Are no longer relevant in modern security
✅ Answer: B. Ensure systems are evaluated and approved for use
Explanation: Certification evaluates system security; accreditation is formal approval to operate.
Q85. What is security assurance?
A. The guarantee that a system will never be hacked
B. The degree of confidence in the security measures of a system
C. The encryption strength used in communications
D. The total cost of system security
✅ Answer: B. The degree of confidence in the security measures of a system
Explanation: Assurance measures how well a system enforces its security policies and withstands threats.
Q86. The ring protection model in computer security is used to:
A. Provide encryption for network traffic
B. Separate levels of privilege within the operating system
C. Implement mandatory access control
D. Isolate malware infections
✅ Answer: B. Separate levels of privilege within the operating system
Explanation: Ring-based protection assigns privilege levels, with Ring 0 being the most privileged.
Q87. What is the purpose of a security perimeter in computer systems?
A. To define the trusted boundary of the system
B. To act as a firewall
C. To stop phishing attacks
D. To separate applications from data
✅ Answer: A. To define the trusted boundary of the system
Explanation: A security perimeter defines what is trusted (inside TCB) vs untrusted (outside).
Q88. Which access control model is considered the most flexible?
A. DAC
B. MAC
C. RBAC
D. ABAC
✅ Answer: D. ABAC
Explanation: Attribute-Based Access Control (ABAC) provides fine-grained access decisions based on user, object, and environment attributes.
Q89. Which evaluation standard provides Protection Profiles and Security Targets?
A. TCSEC
B. ITSEC
C. Common Criteria
D. ISO 27001
✅ Answer: C. Common Criteria
Explanation: Common Criteria defines security functional requirements and evaluation assurance through Protection Profiles and Security Targets.
Q90. Which of the following is NOT part of the TCB?
A. Security kernel
B. Reference monitor
C. User applications
D. Access control mechanisms
✅ Answer: C. User applications
Explanation: User applications are outside the TCB. Only components enforcing the security policy are part of it.
Q91. What is the main focus of the Bell-LaPadula model?
A. Availability
B. Integrity
C. Confidentiality
D. Authentication
✅ Answer: C. Confidentiality
Explanation: Bell-LaPadula ensures sensitive information is not disclosed to unauthorized subjects.
Q92. The Biba model prevents:
A. Unauthorized disclosure of information
B. Unauthorized modification of data
C. Conflict of interest
D. Unauthorized system shutdowns
✅ Answer: B. Unauthorized modification of data
Explanation: Biba enforces rules to maintain data integrity.
Q93. The Clark-Wilson model enforces integrity through:
A. Encryption
B. Well-formed transactions and separation of duties
C. Trusted paths
D. Security labels
✅ Answer: B. Well-formed transactions and separation of duties
Explanation: These ensure only authorized processes can modify data and no single individual can bypass controls.
Q94. Which of the following is a state machine model?
A. Bell-LaPadula
B. Biba
C. Clark-Wilson
D. All of the above
✅ Answer: D. All of the above
Explanation: These models use the state machine concept, defining allowed system states and transitions.
Q95. The Graham-Denning model is primarily concerned with:
A. Integrity
B. Confidentiality
C. Secure creation and deletion of objects and subjects
D. Trusted paths
✅ Answer: C. Secure creation and deletion of objects and subjects
Explanation: Graham-Denning defines rules for securely creating, deleting, and managing subjects and objects.
Q96. Which of the following best describes the Harrison-Ruzzo-Ullman model?
A. It expands DAC by adding more administrative rights
B. It enforces integrity using separation of duties
C. It prevents covert channel communication
D. It implements role-based access control
✅ Answer: A. It expands DAC by adding more administrative rights
Explanation: The HRU model extends discretionary access control to include dynamic rights assignments.
Q97. Which model uses the concept of lattices to control access?
A. Biba
B. Clark-Wilson
C. Bell-LaPadula
D. Lattice-Based Access Control (LBAC)
✅ Answer: D. Lattice-Based Access Control (LBAC)
Explanation: LBAC organizes access permissions using mathematical lattices, useful in multilevel security.
Q98. Which of the following is an example of security assurance requirement in Common Criteria?
A. Security functional requirements
B. Evaluation Assurance Levels (EALs)
C. Protection Profiles
D. Security Targets
✅ Answer: B. Evaluation Assurance Levels (EALs)
Explanation: EALs (1–7) define the depth of evaluation assurance required for a product.
Q99. Which model protects against conflicts of interest in financial organizations?
A. Biba
B. Clark-Wilson
C. Brewer-Nash
D. Bell-LaPadula
✅ Answer: C. Brewer-Nash
Explanation: Brewer-Nash dynamically restricts access to prevent users from accessing conflicting datasets.
Q100. Which of the following is the most widely recognized security evaluation standard today?
A. TCSEC (Orange Book)
B. ITSEC
C. Common Criteria (ISO/IEC 15408)
D. NIST Cybersecurity Framework
✅ Answer: C. Common Criteria (ISO/IEC 15408)
Explanation: Common Criteria replaced TCSEC and ITSEC and is now the global standard for security evaluations.
You’ve completed 50 CompTIA Security+ Security Architecture & Design MCQs with explanations. These practice questions help strengthen your understanding of secure design principles and architecture frameworks critical for passing the Security+ (SY0-701) exam.
Batch 1 (1–50): Threats, Attacks & Vulnerabilities
Batch 3 (101–150): Implementation (Access, Authentication, PKI)
Batch 4 (151–200): Operations & Incident Response
Batch 5 (201–250): Governance, Risk & Compliance
Batch 6 (251–300): Cryptography & PKI
Batch 7 (301–350): Mixed Practice Exam (Past Questions)
Keep practicing consistently, and you’ll be fully prepared for Security+ certification