- A
Signing the image with Cosign and verifying the signature before deployment
Image signing ensures the image has not been tampered with and originated from a trusted source.
- B
Running the container in a separate namespace
Why wrong: Namespaces provide isolation but do not verify image integrity.
- C
Using a SHA256 digest instead of a tag in the image reference
A digest uniquely identifies the image content, preventing tag mutability attacks.
- D
Scanning the image for vulnerabilities using Trivy
Why wrong: Vulnerability scanning finds known security issues but does not verify integrity or authenticity.
- E
Using a base image with the latest tag
Why wrong: Using 'latest' is not a verification method; it can actually lead to integrity issues.
Question 678 of 997
Verify Image Integrity with SHA256 Digest and Cosign Signatures
This CKS practice question tests your understanding of supply chain security. 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.
Which TWO of the following are valid methods to verify the integrity of a container image in a Kubernetes supply chain? (Select 2)
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
✓
Signing the image with Cosign and verifying the signature before deployment
Option A is correct because Cosign is a tool for signing container images using cryptographic keys, and verifying the signature before deployment ensures that the image has not been tampered with since it was signed. This provides integrity and authenticity in the software supply chain, as the signature can be validated against a trusted public key or a keyless identity (e.g., via Fulcio).
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.
- ✓
Signing the image with Cosign and verifying the signature before deployment
Why this is correct
Image signing ensures the image has not been tampered with and originated from a trusted source.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Running the container in a separate namespace
Why it's wrong here
Namespaces provide isolation but do not verify image integrity.
- ✓
Using a SHA256 digest instead of a tag in the image reference
Why this is correct
A digest uniquely identifies the image content, preventing tag mutability attacks.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Scanning the image for vulnerabilities using Trivy
Why it's wrong here
Vulnerability scanning finds known security issues but does not verify integrity or authenticity.
- ✗
Using a base image with the latest tag
Why it's wrong here
Using 'latest' is not a verification method; it can actually lead to integrity issues.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The CNCF CKS exam often tests the distinction between integrity verification (e.g., signatures, digests) and other security practices like vulnerability scanning or namespace isolation, leading candidates to mistakenly select scanning or isolation as valid integrity checks.
Detailed technical explanation
How to think about this question
Cosign leverages Sigstore's infrastructure, including Fulcio for certificate-based signing and Rekor for transparency logs, enabling keyless signing and verification. Using a SHA256 digest (option C) pins the image to an immutable content hash, ensuring that the exact same image is pulled every time, which is a fundamental integrity check against tag mutability attacks. In practice, combining digest pinning with Cosign signatures provides defense-in-depth against both accidental and malicious image substitution.
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.
- →
Supply Chain Security — study guide chapter
Learn the concepts, then practise the questions
- →
Supply Chain Security practice questions
Targeted practice on this topic area only
- →
All CKS questions
997 questions across all exam domains
- →
Certified Kubernetes Security Specialist CKS study guide
Full concept coverage aligned to exam objectives
- →
CKS practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related CKS practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Monitoring Logging and Runtime Security practice questions
Practise CKS questions linked to Monitoring Logging and Runtime Security.
Cluster Setup and Hardening practice questions
Practise CKS questions linked to Cluster Setup and Hardening.
System Hardening practice questions
Practise CKS questions linked to System Hardening.
Minimize Microservice Vulnerabilities practice questions
Practise CKS questions linked to Minimize Microservice Vulnerabilities.
Supply Chain Security practice questions
Practise CKS questions linked to Supply Chain Security.
Monitoring, Logging and Runtime Security practice questions
Practise CKS questions linked to Monitoring, Logging and Runtime Security.
Cluster Setup practice questions
Practise CKS questions linked to Cluster Setup.
Cluster Hardening practice questions
Practise CKS questions linked to Cluster Hardening.
CKS fundamentals practice questions
Practise CKS questions linked to CKS fundamentals.
CKS scenario practice questions
Practise CKS questions linked to CKS scenario.
CKS troubleshooting practice questions
Practise CKS questions linked to CKS troubleshooting.
Practice this exam
Start a free CKS 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 CKS question test?
Supply Chain Security — This question tests Supply Chain Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Signing the image with Cosign and verifying the signature before deployment — Option A is correct because Cosign is a tool for signing container images using cryptographic keys, and verifying the signature before deployment ensures that the image has not been tampered with since it was signed. This provides integrity and authenticity in the software supply chain, as the signature can be validated against a trusted public key or a keyless identity (e.g., via Fulcio).
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.
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 →
Same concept, more angles
2 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. Which TWO of the following are valid methods to verify the integrity of a container image? (Select 2)
medium- A.Use trivy image to check for vulnerabilities
- ✓ B.Compare the image SHA digest with a known good digest
- ✓ C.Use cosign verify to check the image signature
- D.Use docker history to view layers
- E.Use kubectl describe pod to check image details
Why B: Option B is correct because container images are identified by a content-addressable digest (SHA256 hash) that uniquely represents the image manifest. Verifying that the SHA digest of a pulled image matches a known good digest from a trusted source ensures the image has not been tampered with or altered in transit, as any change to the image layers or configuration would result in a different digest.
Variation 2. Which TWO of the following are valid methods to verify the integrity of a container image before deployment?
medium- A.Run a vulnerability scan on the image
- B.Use the latest tag to ensure the most recent version
- C.Generate an SBOM for the image
- ✓ D.Use the image digest (SHA256) instead of a tag
- ✓ E.Verify the image signature using Cosign
Why D: Option D is correct because using the image digest (SHA256) provides a cryptographic hash of the image manifest, ensuring that the exact same image content is pulled every time, regardless of tag changes. This prevents tag mutability attacks where a malicious actor could overwrite a tag with a compromised image. The digest is immutable and uniquely identifies the image content.
Keep practising
More CKS practice questions
- Which flag is used to restrict the kubelet's ability to modify node status and pods?
- A Falco rule has priority `WARNING` and output: `Sensitive file opened (user=%user.name command=%proc.cmdline file=%fd.n…
- Falco detects a shell being opened inside a container. Which Falco rule field is used to specify the syscall condition f…
- A security audit reveals that a ServiceAccount named 'monitor' has a ClusterRoleBinding to the cluster-admin role. What…
- Match each Kubernetes security component to its description.
- Match each Kubernetes certificate type to its usage.
Last reviewed: Jul 4, 2026
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.
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.