hardMultiple Choice
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A security analyst is reviewing a third-party assessment report and notes that the vendor's encryption algorithms are outdated.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confuse 'technically compliant' with 'secure' and choose to accept the risk (Option D), failing to recognize that outdated encryption algorithms violate the contractual requirement to follow industry best practices, which is a governance and compliance issue, not just a technical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The contract requires the vendor to follow industry best practices, and outdated encryption algorithms (e.g., DES, RC4, or 3DES) are no longer considered secure or compliant with standards like NIST SP 800-131A or PCI DSS.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A penetration test probes for exploitable vulnerabilities; it does not remediate outdated cryptographic algorithms or enforce the contract's best-practices clause. It is tempting because it produces concrete evidence, but penetration testing suits validating controls after remediation, not resolving a known algorithmic weakness.
- ✓
Request the vendor to upgrade encryption algorithms to current standards.
Why this is correct
Requesting an upgrade directly addresses the outdated algorithms, satisfying the contract's industry best-practices requirement. Unlike compensating controls or risk acceptance, remediation eliminates the weak cryptography at source. This is the proportionate response when a vendor's assessed posture breaches a contractual security obligation, restoring compliance without severing the relationship.
- ✗
Terminate the contract immediately.
Why it's wrong here
Termination discards the vendor relationship before any remediation attempt, exceeding the contract's requirement to follow best practices and ignoring the standard remedy path. It is tempting when risk appetite is low, but immediate termination fits only confirmed, unremediable breaches or regulatory prohibition.
- ✗
Accept the risk because the vendor is technically compliant with the contract.
Why it's wrong here
Accepting the risk misreads the contract: outdated algorithms breach the best-practices clause, so the vendor is not compliant. It is tempting when the data is low-sensitivity or compensating controls exist, but acceptance follows documented risk treatment, not a false compliance claim.
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 |
Go deeper
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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.