CAS-004 Security Engineering Practice Question
A company is deploying IoT sensors that require secure firmware updates over the air (OTA). To ensure integrity and authenticity of the firmware, which of the following should be implemented?
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
✓
Code signing with a trusted certificate
Code signing with digital signatures ensures firmware integrity and authenticity. Encryption alone does not guarantee authenticity. Hash verification ensures integrity but not authenticity. Secure boot ensures only signed firmware runs but does not protect the update process itself.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Code signing with a trusted certificate
Why this is correct
Digital signatures verify that the firmware came from a trusted source and hasn't been altered.
- ✗
Secure boot on the device
Why it's wrong here
Secure boot ensures only signed firmware executes, but it doesn't protect the update transmission.
- ✗
Hash verification only
Why it's wrong here
Hash verification detects tampering but does not verify the source.
- ✗
Encryption of the firmware image
Why it's wrong here
Encryption provides confidentiality, not authenticity or integrity.
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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.