You are using AWS S3 to encrypt and store large documents for your application. You have been asked to use the AWS Lambda function for this purpose by your Technical Architect. You have determined the use of AWS KMS for encryption as your data is stored and managed in the AWS platform. Which CMK will you use for this purpose?

Answer options:

A.Asymmetric CMK
B.Symmetric CMK
C.RSA CMK
D.ECC CMK

Answer: B
Option A is incorrect as AWS services that integrate with AWS KMS do not support the use of asymmetric keys.
Option B is CORRECT as mentioned in the documentation. Symmetric keys never leave KMS unencrypted and hence are used to integrate with other AWS services.
Option C is incorrect as RSA CMK is a type of asymmetric key which cannot be used with other AWS services for integration.
Option D is incorrect as ECC CMK is a type of asymmetric key which cannot be used with other AWS services for integration.
Reference:
https://docs.aws.amazon.com/kms/latest/developerguide/symm-asymm-concepts.html#symmetric-cmks