DBS-C01 Database Security Practice Question
A financial services company uses Amazon DynamoDB to store sensitive customer data. The security team requires that all data at rest be encrypted using a customer-managed AWS KMS key (CMK) with automatic rotation enabled. The DynamoDB table was created with the default AWS-managed key. Which steps are necessary to transition to a customer-managed CMK while minimizing downtime and data loss?
⚠ Common exam trap
It's easy for candidates to assume DynamoDB allows in-place encryption key changes (like some other AWS services), but DynamoDB requires a table recreation to change the encryption key, making the export/import workflow necessary.
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
✓
Export the table data to Amazon S3, create a new DynamoDB table with the new CMK, import the data, and update the application to use the new table.
DynamoDB does not support in-place modification of the encryption key for an existing table. To transition from an AWS-managed key to a customer-managed CMK, you must export the table data to Amazon S3, create a new DynamoDB table configured with the new CMK, import the data, and update the application to point to the new table. This approach minimizes downtime by allowing the original table to serve reads/writes during the export and import process, and avoids data loss by using DynamoDB's native export and import features.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Modify the DynamoDB table to update the encryption key to the new CMK using the AWS Console.
Why it's wrong here
DynamoDB does not support modifying the encryption key on an existing table.
- ✓
Export the table data to Amazon S3, create a new DynamoDB table with the new CMK, import the data, and update the application to use the new table.
Why this is correct
This is the only way to change the encryption key, as DynamoDB does not allow in-place key changes.
- ✗
Disable encryption at rest, then re-enable it with the new CMK.
Why it's wrong here
Encryption at rest cannot be disabled on a DynamoDB table; it is always enabled.
- ✗
Update the KMS key policy to grant DynamoDB access to the new CMK, then rotate the key.
Why it's wrong here
The key policy change does not change the key used to encrypt the table; the table will still use the original key.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
Related to this question
About these practice questions
One of 1,663 original DBS-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-C01 practice question is part of Courseiva's free Amazon Web Services 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 DBS-C01 exam.