Question 409 of 997
Minimize Microservice VulnerabilitieshardMultiple ChoiceObjective-mapped

Encrypt Secrets at Rest

This CKS practice question tests your understanding of minimize microservice vulnerabilities. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.

You need to encrypt Secrets at rest in an existing Kubernetes cluster. You create an EncryptionConfiguration file specifying aescbc as the provider. After updating the API server kube-apiserver.yaml with the new configuration, you create a new Secret. Which of the following statements is true?

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

Only newly created secrets will be encrypted; existing secrets remain unencrypted.

Option A is correct because the EncryptionConfiguration only applies to data written to etcd after the API server is restarted with the new configuration. Existing Secrets that were stored in etcd before the restart remain in their original unencrypted form unless they are explicitly rewritten (e.g., by deleting and recreating them or using a tool like `kubectl get secret ... -o yaml | kubectl replace -f -`). The `aescbc` provider encrypts new data at rest, but does not retroactively encrypt 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.

  • Only newly created secrets will be encrypted; existing secrets remain unencrypted.

    Why this is correct

    EncryptionConfiguration applies at write time. Existing secrets stored in etcd remain unencrypted until they are modified.

    Related concept

    Read the scenario before looking for a memorised answer.

  • The encryption key is automatically rotated every 30 days.

    Why it's wrong here

    Key rotation is manual; it is not automatic.

  • The aescbc provider can be changed to identity without any impact on existing secrets.

    Why it's wrong here

    Changing the provider affects only new writes; existing secrets encrypted with the old provider would become unreadable if the provider is removed.

  • All existing secrets in the cluster are automatically encrypted after the API server restart.

    Why it's wrong here

    Existing secrets are not encrypted until they are written again. Only new or updated secrets are encrypted.

Common exam traps

Common exam trap: answer the scenario, not the keyword

A common misconception is that restarting the API server with an EncryptionConfiguration retroactively encrypts existing data, but actually only new writes are encrypted.

Detailed technical explanation

How to think about this question

Under the hood, Kubernetes uses the EncryptionConfiguration to define a list of providers that are tried in order for encryption and decryption. When a Secret is written, the first provider in the list (e.g., `aescbc`) encrypts the data before storing it in etcd. When reading, providers are tried in order until one can decrypt the data. This means that if you later remove the old provider, existing encrypted secrets become unreadable. A common real-world scenario is that after enabling encryption, operators must use a script to re-encode all existing secrets (e.g., `kubectl get secrets --all-namespaces -o json | kubectl replace -f -`) to ensure they are encrypted.

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 CKS 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.

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FAQ

Questions learners often ask

What does this CKS question test?

Minimize Microservice Vulnerabilities — This question tests Minimize Microservice Vulnerabilities — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Only newly created secrets will be encrypted; existing secrets remain unencrypted. — Option A is correct because the EncryptionConfiguration only applies to data written to etcd after the API server is restarted with the new configuration. Existing Secrets that were stored in etcd before the restart remain in their original unencrypted form unless they are explicitly rewritten (e.g., by deleting and recreating them or using a tool like `kubectl get secret ... -o yaml | kubectl replace -f -`). The `aescbc` provider encrypts new data at rest, but does not retroactively encrypt existing data.

What should I do if I get this CKS 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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Same concept, more angles

1 more ways this is tested on CKS

These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.

Variation 1. You need to encrypt secrets at rest in a Kubernetes cluster. What must be configured?

medium
  • A.Create an EncryptionConfiguration object in the cluster and pass it to kube-apiserver via --encryption-provider-config
  • B.Set the environment variable ENCRYPT_SECRETS=true on the kube-controller-manager
  • C.Use a MutatingWebhookConfiguration to encrypt secrets before storage
  • D.Enable the 'SecretEncryption' feature gate on all control plane components

Why A: Option A is correct because Kubernetes encrypts secrets at rest by defining an EncryptionConfiguration object that specifies which encryption providers (e.g., AES-CBC, secretbox, or KMS) to use, and then passing the configuration file to the kube-apiserver via the `--encryption-provider-config` flag. This ensures that when the API server writes secrets to etcd, they are encrypted before storage, and decrypted on read, meeting the requirement for encrypting secrets at rest.

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Last reviewed: Jul 4, 2026

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This CKS practice question is part of Courseiva's free CNCF 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 CKS exam.