Question 470 of 514
Explain encryption as a servicehardMultiple ChoiceObjective-mapped

VA-003 Explain encryption as a service Practice Question

This VA-003 practice question tests your understanding of explain encryption as a service. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.

Exhibit

Refer to the exhibit.

```
$ vault write -f transit/keys/payment-key
Success! Data written to: transit/keys/payment-key

$ vault write transit/encrypt/payment-key plaintext=$(base64 <<< "4111111111111111")
Key        Value
---        -----
ciphertext vault:v1:abc123...

$ vault write -f transit/keys/payment-key/rotate
Success! Data written to: transit/keys/payment-key/rotate

$ vault write transit/encrypt/payment-key plaintext=$(base64 <<< "4111111111111111")
Key        Value
---        -----
ciphertext vault:v2:def456...

$ vault write transit/decrypt/payment-key ciphertext=vault:v1:abc123...
Key          Value
---          -----
plaintext    NDExMTExMTExMTExMTExMQ==
```

After rotating the 'payment-key', Vault successfully decrypts data encrypted with the old key (v1). What is the most likely reason the decryption succeeded?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "most likely"

    Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

Question 1hardmultiple choice
Full question →

Exhibit

Refer to the exhibit.

```
$ vault write -f transit/keys/payment-key
Success! Data written to: transit/keys/payment-key

$ vault write transit/encrypt/payment-key plaintext=$(base64 <<< "4111111111111111")
Key        Value
---        -----
ciphertext vault:v1:abc123...

$ vault write -f transit/keys/payment-key/rotate
Success! Data written to: transit/keys/payment-key/rotate

$ vault write transit/encrypt/payment-key plaintext=$(base64 <<< "4111111111111111")
Key        Value
---        -----
ciphertext vault:v2:def456...

$ vault write transit/decrypt/payment-key ciphertext=vault:v1:abc123...
Key          Value
---          -----
plaintext    NDExMTExMTExMTExMTExMQ==
```

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

The old key version is retained and used for decryption when the ciphertext references that version.

A is correct because Vault uses key versioning: when a key is rotated, the old key version (v1) is retained for decryption purposes. The ciphertext includes metadata referencing the key version used for encryption, so Vault automatically selects the correct old key version to decrypt data encrypted before rotation. This ensures backward compatibility without re-encrypting existing data.

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.

  • The old key version is retained and used for decryption when the ciphertext references that version.

    Why this is correct

    Vault retains old key versions for decryption, and the ciphertext includes the version identifier, allowing decryption with the appropriate key.

    Clue confirmation

    The clue word "most likely" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

  • The old key version is automatically deleted after rotation, but the ciphertext contains the key version and is decrypted by the new key.

    Why it's wrong here

    Old key versions are retained for decryption; they are not deleted automatically.

  • The ciphertext contains the original plaintext, so decryption simply extracts it.

    Why it's wrong here

    Ciphertext is not plaintext; it is encrypted data that requires the correct key to decrypt.

  • The plaintext is stored in Vault during encryption, so decryption retrieves the stored plaintext.

    Why it's wrong here

    Vault does not store the plaintext; it only returns the ciphertext.

Common exam traps

Common exam trap: answer the scenario, not the keyword

HashiCorp often tests the misconception that key rotation invalidates old ciphertext, but the trap here is that candidates assume the old key is deleted or replaced, when in fact Vault retains it for decryption based on ciphertext metadata.

Detailed technical explanation

How to think about this question

Vault's transit secrets engine implements key rotation by creating a new key version (e.g., v2) while preserving the previous version (v1) in a key ring. When decrypting, Vault inspects the ciphertext's key_version parameter (part of the wrapped key or context) to select the appropriate key material. This design is critical for compliance scenarios where data encrypted under a deprecated key must remain accessible until re-encryption is performed, avoiding data loss.

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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.

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.

Related practice questions

Related VA-003 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free VA-003 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

FAQ

Questions learners often ask

What does this VA-003 question test?

Explain encryption as a service — This question tests Explain encryption as a service — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: The old key version is retained and used for decryption when the ciphertext references that version. — A is correct because Vault uses key versioning: when a key is rotated, the old key version (v1) is retained for decryption purposes. The ciphertext includes metadata referencing the key version used for encryption, so Vault automatically selects the correct old key version to decrypt data encrypted before rotation. This ensures backward compatibility without re-encrypting existing data.

What should I do if I get this VA-003 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Are there clue words in this question I should notice?

Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

What is the key concept behind this question?

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 →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 30, 2026

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.

Loading comments…

Sign in to join the discussion.

This VA-003 practice question is part of Courseiva's free HashiCorp 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 VA-003 exam.