The correct answer is to use encryption for data at rest and in transit, as it is the only control that directly safeguards both states. Encryption renders data unreadable without the proper decryption key, protecting confidentiality and integrity whether the data is stored on a database server (e.g., AES-256) or transmitted over a network (e.g., TLS 1.3 for HTTPS). On the CISA exam, this concept tests your understanding of how encryption uniquely addresses dual-state protection, often appearing in scenario-based questions where other controls like firewalls or access controls only cover one state. A common trap is choosing a control that protects only data in transit, such as a VPN, while neglecting data at rest. Remember the memory tip: “Encrypt both ends, rest and sends”—if data is encrypted when stored and when moving, it remains secure regardless of interception.
CISA Protection of Information Assets Practice Question
This CISA practice question tests your understanding of protection of information assets. Compare every option against the stated constraints before choosing — the best answer satisfies all requirements, not just the most obvious one. 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.
A small business wants to protect customer data collected through its e-commerce website. Which control is most appropriate for protecting the data at rest and in transit?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use encryption for data at rest and in transit.
Encryption is the only control that directly protects the confidentiality and integrity of data both at rest (e.g., AES-256 for database files) and in transit (e.g., TLS 1.3 for HTTPS). It renders data unreadable without the proper decryption key, ensuring that even if storage media or network traffic is intercepted, the customer data remains secure.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Implement a network firewall to block unauthorized access.
Why it's wrong here
Firewalls protect the network perimeter but do not encrypt data, so they are insufficient for protecting data at rest and in transit.
✗
Perform regular backups of the database to ensure data availability.
Why it's wrong here
Backups ensure data can be restored but do not protect confidentiality or prevent unauthorized access.
✗
Deploy an intrusion detection system (IDS) to monitor for threats.
Why it's wrong here
IDS detects potential attacks but does not protect data confidentiality or encrypt it.
✓
Use encryption for data at rest and in transit.
Why this is correct
Encryption directly protects data confidentiality by making it unreadable without the decryption key, applicable both at rest and in transit.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse preventive controls like firewalls or IDS with data protection mechanisms, failing to recognize that encryption is the only direct safeguard for data confidentiality both at rest and in transit.
Detailed technical explanation
How to think about this question
For data at rest, full-disk encryption (e.g., BitLocker, LUKS) or column-level encryption (e.g., AES-256 in MySQL) protects stored data, while for data in transit, TLS 1.3 uses ephemeral Diffie-Hellman key exchange to provide forward secrecy. A common real-world scenario is a database backup file stolen from an unencrypted storage bucket—without encryption at rest, the data is immediately readable. Additionally, encryption alone must be paired with proper key management (e.g., using a hardware security module) to avoid key compromise.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the CISA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Protection of Information Assets — This question tests Protection of Information Assets — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use encryption for data at rest and in transit. — Encryption is the only control that directly protects the confidentiality and integrity of data both at rest (e.g., AES-256 for database files) and in transit (e.g., TLS 1.3 for HTTPS). It renders data unreadable without the proper decryption key, ensuring that even if storage media or network traffic is intercepted, the customer data remains secure.
What should I do if I get this CISA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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This CISA practice question is part of Courseiva's free ISACA 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 CISA exam.
Question Discussion
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