Migrating AWS KMS Customer Keys from US East to EU Central Region

Migrating AWS KMS Customer Keys to EU Central Region

Question

Your application currently uses customer keys which are generated via AWS KMS in the US east region.

You now want to use the same set of keys from the EU-Central region.

How can this be accomplished?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

Answer: D.

AWS KMS supports multi-region keys, which are AWS KMS keys in different AWS Regions that can be used interchangeably - as though you had the same key in multiple Regions.

With multi-Region keys, you can more easily move encrypted data between Regions without having to decrypt and re-encrypt with different keys in each Region.

Multi-Region keys are not global.

You create a multi-Region primary key and then replicate it into Regions that you select within an AWS partition.

Then you manage the multi-Region key in each Region independently.

Neither AWS nor AWS KMS ever automatically creates or replicates multi-Region keys into any Region on your behalf.

Option A is incorrect because neither AWS nor AWS KMS automatically replicates any keys into another Region.

Option B is incorrect because key rotation cannot be used to export keys.

Option C is incorrect because the backing key cannot be used to export keys.

Option D is CORRECT because multi-Region keys have the capability to replicate keys from one AWS Region into another.

For more information on KMS keys, kindly refer to the following URL:

https://aws.amazon.com/about-aws/whats-new/2021/06/kms-multi-region-keys/ https://docs.aws.amazon.com/kms/latest/developerguide/multi-region-keys-overview.html

Option A is not entirely accurate because while AWS KMS does automatically replicate keys to multiple regions, it is not guaranteed to happen immediately and might not always be desirable.

Option B involves key rotation, which is a process of creating a new key while the old key is still in use. This method can work, but it might be inefficient since it requires creating a new key for each region where you want to use the key.

Option C is not a recommended practice since it can introduce security risks. The backing key should always be kept secret and not shared between different regions.

Option D, using multi-Region keys in AWS KMS, is the recommended solution. Multi-Region keys allow you to create a single key that can be used across multiple regions. This key is backed by a set of regional keys that are created and managed by AWS KMS automatically. The regional keys are used to perform cryptographic operations within their respective regions, while the multi-Region key is used to manage the key material and metadata for the key. This approach provides a secure and efficient way to use a single key across multiple regions.