CAS-004 Security Engineering Practice Question
A company wants to implement certificate pinning for its mobile app to prevent man-in-the-middle attacks. Which approach is most secure and maintainable?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Pin the SHA-256 hash of the server's public key.
Pinning the public key hash rather than the certificate itself allows certificate rotation without updating the app, as long as the key pair remains the same.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Pin the entire certificate chain, including the root CA certificate.
Why it's wrong here
Pinning the root CA is too broad; any certificate from that CA would be accepted.
- ✓
Pin the SHA-256 hash of the server's public key.
Why this is correct
This allows certificate renewal without changing the key, providing flexibility and security.
- ✗
Pin the Subject Public Key Info (SPKI) using base64 encoding.
Why it's wrong here
This is similar to pinning the public key, but using the hash is more standard and efficient.
- ✗
Pin the issuing CA certificate only.
Why it's wrong here
If the issuing CA is compromised, the pin is bypassed; also does not protect against CA-issued rogue certs.
Go deeper
Related to this question
About these practice questions
This CAS-005 question is part of Courseiva's 968-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CAS-005 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CAS-005 exam.