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ISC2 CC Practice Question: A company's security policy requires that all…
A company's security policy requires that all sensitive data be encrypted both at rest and in transit. This is an example of applying which security principle?
⚠ Common exam trap
Many candidates confuse access-control principles (least privilege, need to know, separation of duties) with data-protection layering; candidates who see 'encryption' and reach for an access-control answer miss that the question is about layered controls, not authorization.
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
✓
Defense in depth
Encrypting sensitive data both at rest and in transit applies multiple overlapping controls at different layers of the environment, which is the definition of defense in depth. Rather than relying on a single control, the organization layers cryptographic protections so that compromise of one layer (e.g., a stolen disk) does not automatically expose the data. This is a classic example of layered, redundant security controls.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Separation of duties
Why it's wrong here
Separation of duties divides critical tasks among different people to prevent fraud and error; it says nothing about protecting data through encryption. It is tempting as a governance control, but encryption at rest and in transit is an implementation of the defence-in-depth principle, layering safeguards across data states.
- ✗
Need to know
Why it's wrong here
Need to know limits access to data to individuals whose job requires it; it governs who may view information, not whether that information is encrypted. The policy here mandates encryption in storage and transmission. Need to know would be correct if the requirement restricted data access to specific authorised staff.
- ✗
Least privilege
Why it's wrong here
Least privilege restricts each identity's permissions to the minimum needed for its tasks; it governs authorisation scope, not data encryption. Encryption at rest and in transit is a data-protection control. Least privilege would be the right answer if the policy limited administrators to only the roles their duties require.
- ✓
Defense in depth
Why this is correct
Defense in depth layers multiple independent controls so that a failure in one does not expose data. Encrypting sensitive data both at rest and in transit applies two complementary safeguards across different states, matching that layered principle.
Go deeper
Related to this question
Learn chapter
Access Control Fundamentals
Key term
Organization
An Organization is a top-level container in Google Cloud that represents your company or entities and serves as the root node for all your cloud resources, policies, and access control.
Key term
Policy
A policy is a set of rules or guidelines that defines how an organization manages, secures, and operates its IT systems and services.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official ISC2 exam blueprint
This CC 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 CC exam.