SSCP Security Architecture & Engineering 5 — Questions and Answers
Question 1: Which of the following correctly describes the Clark-Wilson security model's primary focus?
- Preventing information flow from high to low classification levels
- Ensuring data integrity through well-formed transactions and separation of duties (Correct answer)
- Controlling access based on subjects' need-to-know clearances
- Protecting against covert channel communications in military systems
Correct answer: Ensuring data integrity through well-formed transactions and separation of duties
The Clark-Wilson model focuses on data integrity by requiring that all data transformations occur through constrained (well-formed) transactions and enforces separation of duties to prevent fraud.
Question 2: A security team is evaluating whether to use symmetric or asymmetric encryption for bulk data encryption at rest. What is the PRIMARY reason to choose symmetric encryption for this use case?
- Symmetric encryption provides stronger mathematical guarantees than asymmetric
- Symmetric encryption is significantly faster and more efficient for encrypting large data volumes (Correct answer)
- Symmetric encryption does not require key exchange protocols
- Symmetric encryption keys are easier to revoke than asymmetric key pairs
Correct answer: Symmetric encryption is significantly faster and more efficient for encrypting large data volumes
Symmetric encryption algorithms (AES, ChaCha20) are orders of magnitude faster than asymmetric algorithms (RSA, ECC), making them the practical choice for encrypting large volumes of data at rest.
Question 3: What is the main security purpose of certificate pinning in mobile applications?
- Preventing the application from connecting to unauthorized Wi-Fi networks
- Preventing MITM attacks by validating the server's certificate against a known-good copy (Correct answer)
- Ensuring the device's operating system is up to date before connecting
- Preventing the application from using expired certificates
Correct answer: Preventing MITM attacks by validating the server's certificate against a known-good copy
Certificate pinning hardcodes the expected server certificate or public key in the application, preventing man-in-the-middle attacks that use rogue but CA-trusted certificates.
Question 4: In the context of secure system design, what is a 'trusted computing base' (TCB)?
- The set of hardware, software, and firmware components critical to enforcing the security policy (Correct answer)
- The baseline configuration of a hardened operating system image
- The collection of security tools deployed on a network segment
- The group of administrators with privileged access to production systems
Correct answer: The set of hardware, software, and firmware components critical to enforcing the security policy
The Trusted Computing Base is the totality of protection mechanisms within a computer system — including hardware, firmware, and software — that are relied upon to enforce the security policy.
Question 5: Which security architecture principle advocates that a security mechanism's design should be open to public scrutiny rather than kept secret?
- Least Privilege
- Open Design (Correct answer)
- Complete Mediation
- Psychological Acceptability
Correct answer: Open Design
The Open Design principle (from Saltzer and Schroeder) states that security should not depend on the secrecy of the mechanism itself, but rather on the secrecy of keys or other parameters.
Question 6: An engineer is selecting an asymmetric algorithm for key exchange in a forward-secret TLS configuration. Which algorithm is most appropriate?
- RSA Key Encipherment
- Ephemeral Diffie-Hellman (DHE) or ECDHE (Correct answer)
- DSA (Digital Signature Algorithm)
- El Gamal Encryption
Correct answer: Ephemeral Diffie-Hellman (DHE) or ECDHE
DHE and ECDHE use ephemeral (temporary) key pairs for each session, providing forward secrecy — compromise of the server's long-term private key does not expose past session keys.
Question 7: What is the primary security risk addressed by implementing micro-segmentation in a data center network?
- Preventing DDoS attacks from external threat actors
- Limiting lateral movement by attackers who have breached the perimeter (Correct answer)
- Reducing the attack surface of internet-facing web applications
- Preventing insider threats from accessing HR database servers
Correct answer: Limiting lateral movement by attackers who have breached the perimeter
Micro-segmentation divides the network into small, isolated zones with granular access controls, limiting an attacker's ability to move laterally between workloads after an initial breach.
SSCP Security Architecture & Engineering 5
Which of the following correctly describes the Clark-Wilson security model's primary focus?