Quick Answer
The answer is encryption of files, as it directly protects data at rest on endpoint devices by rendering the information unreadable without the correct decryption key. This technical concept ensures confidentiality even if a laptop or mobile device is lost or stolen, because the encrypted data remains inaccessible to unauthorized users. On the CISSP exam, this question tests your understanding of how DLP for data at rest integrates with endpoint encryption technologies like BitLocker or FileVault to enforce policy-based protection. A common trap is confusing data-at-rest controls with data-in-transit solutions such as TLS or network DLP; remember that endpoint encryption is the primary defense when the device itself is the attack vector. For a quick memory tip, think “REST = ENCRYPT” — when data is resting on an endpoint, encryption is the lock that keeps it safe.
This CISSP practice question tests your understanding of security operations. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An organization implements a data loss prevention (DLP) solution. Which action is most effective for protecting data at rest on endpoint devices?
Encryption of files
Directly protects data at rest on endpoints.
User awareness training
Why wrong: Reduces risk but does not directly protect data at rest.
USB port blocking
Why wrong: Prevents data exfiltration via USB but does not protect stored data.
Network DLP monitoring
Why wrong: Monitors data in transit, not at rest.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Encryption of files
Encryption of files directly protects data at rest on endpoint devices by rendering the data unreadable without the appropriate decryption key. This ensures that even if an endpoint is lost, stolen, or accessed by an unauthorized user, the data remains confidential. DLP solutions often integrate with file-level encryption (e.g., BitLocker, FileVault, or EFS) to enforce policy-based encryption on sensitive files at rest.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Encryption of files
Why this is correct
Directly protects data at rest on endpoints.
Related concept
Read the scenario before looking for a memorised answer.
User awareness training
Why it's wrong here
Reduces risk but does not directly protect data at rest.
USB port blocking
Why it's wrong here
Prevents data exfiltration via USB but does not protect stored data.
Network DLP monitoring
Why it's wrong here
Monitors data in transit, not at rest.
Common exam traps
ISC2 often tests the distinction between data states (at rest, in motion, in use) and the specific controls that apply to each; the trap here is that candidates confuse network DLP (data in motion) with endpoint DLP (data at rest), or they select a general security control like user training instead of the direct technical control for data at rest.
Detailed technical explanation
File-level encryption for data at rest typically uses symmetric encryption algorithms such as AES-256, with keys managed via a key management system (KMS) or TPM (Trusted Platform Module) on the endpoint. In a DLP context, classification labels can trigger automatic encryption policies—for example, a file tagged as 'Confidential' may be encrypted by the DLP agent using EFS (Encrypting File System) on Windows or FileVault on macOS. A subtle behavior: if the encryption key is stored on the same endpoint (e.g., in the TPM), a sophisticated attacker with physical access might extract the key via cold boot attacks, so enterprise DLP solutions often enforce key escrow or remote key retrieval from a central server.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A developer is choosing between AES-256 (symmetric) and RSA-2048 (asymmetric) for encrypting a large file that will be sent to a partner. Symmetric encryption is fast but requires key exchange; asymmetric is slower but solves the key distribution problem. A hybrid approach — encrypt the file with AES, encrypt the AES key with RSA — is standard. Questions like this test whether you understand when each approach applies.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Security Operations — study guide chapter
Learn the concepts, then practise the questions
Security Operations practice questions
Targeted practice on this topic area only
All CISSP questions
529 questions across all exam domains
Certified Information Systems Security Professional CISSP study guide
Full concept coverage aligned to exam objectives
CISSP practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise CISSP questions linked to Software Development Security.
Practise CISSP questions linked to Security Assessment and Testing.
Practise CISSP questions linked to Identity and Access Management.
Practise CISSP questions linked to Security and Risk Management.
Practise CISSP questions linked to Security Architecture and Engineering.
Practise CISSP questions linked to Communication and Network Security.
Practise CISSP questions linked to Asset Security.
Practise CISSP questions linked to Security Operations.
Practise CISSP questions linked to CISSP fundamentals.
Practise CISSP questions linked to CISSP scenario.
Practise CISSP questions linked to CISSP troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Security Operations — This question tests Security Operations — Read the scenario before looking for a memorised answer..
The correct answer is: Encryption of files — Encryption of files directly protects data at rest on endpoint devices by rendering the data unreadable without the appropriate decryption key. This ensures that even if an endpoint is lost, stolen, or accessed by an unauthorized user, the data remains confidential. DLP solutions often integrate with file-level encryption (e.g., BitLocker, FileVault, or EFS) to enforce policy-based encryption on sensitive files at rest.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 30, 2026
This CISSP practice question is part of Courseiva's free ISC2 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 CISSP exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.