A company has a large set of keys defined in AWS KMS. The application uses the keys frequently. What is one of the ways that can be used to reduce the cost of accessing the keys in the AWS KMS service?

Answer options:

A.Enable rotation of the keys.
B.Use Data key caching.
C.Create an alias of the key.
D.Use the right key policy.

Answer: B
Option A is incorrect because enabling key rotation would not help reduce the cost of accessing the keys.
Option B is CORRECT because data key caching stores data keys and related cryptographic material in a cache. When you encrypt or decrypt data, the AWS Encryption SDK looks for a matching data key in the cache. If it finds a match, it uses the cached data key rather than generates a new one. Data key caching can improve performance, reduce cost, and help you stay within service limits as your application scales.
Option C is incorrect because creating aliases for the key would not impact how the key is used and not reduce the access request.
Option D is incorrect because providing a key policy would not impact how the key is used and not reduce the access request.
For more information on data key caching, please refer to the below URL:
https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/data-key-caching.html