hardMultiple ChoiceObjective-mapped
CAS-004 Practice Question: A security analyst is reviewing a third-party…
A security analyst is reviewing a third-party assessment report and notes that the vendor's encryption algorithms are outdated. The contract requires the vendor to follow industry best practices. Which of the following is the BEST response?
⚠ Common exam trap
Test-takers frequently confuse 'technically compliant' with 'secure' and choose to accept the risk (Option D), failing to recognize that outdated encryption algorithms violate the contractual requirement to follow industry best practices, which is a governance and compliance issue, not just a technical one.
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
✓
Request the vendor to upgrade encryption algorithms to current standards.
The contract requires the vendor to follow industry best practices, and outdated encryption algorithms (e.g., DES, RC4, or 3DES) are no longer considered secure or compliant with standards like NIST SP 800-131A or PCI DSS. The best response is to formally request the vendor to upgrade to current, approved algorithms such as AES-256 or ChaCha20, as this directly addresses the non-compliance with the contractual requirement. This action aligns with the governance and risk management process of enforcing contractual security obligations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Conduct a penetration test on the vendor's system.
Why it's wrong here
A pen test might not address the algorithm issue and could be outside the scope of the relationship.
- ✓
Request the vendor to upgrade encryption algorithms to current standards.
Why this is correct
Directly asking the vendor to comply with the contract's best-practice clause is the most appropriate first step.
- ✗
Terminate the contract immediately.
Why it's wrong here
Termination should be a last resort after attempts to remedy.
- ✗
Accept the risk because the vendor is technically compliant with the contract.
Why it's wrong here
The contract explicitly requires best practices, so outdated algorithms are non-compliant.
Quick reference
Symmetric Encryption Algorithm Comparison
| Algorithm | Key Size | Block Size | Status | Notes |
|---|---|---|---|---|
| AES-128 | 128-bit | 128-bit | Current standard | NIST approved; WPA3, TLS |
| AES-256 | 256-bit | 128-bit | Current standard | Preferred for sensitive / govt data |
| 3DES | 112-bit effective | 64-bit | Deprecated (2023) | Replaced by AES |
| DES | 56-bit | 64-bit | Broken | Cracked in < 24 h; never deploy |
| ChaCha20 | 256-bit | Stream cipher | Current | TLS 1.3, WireGuard |
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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.