[ aws . ec2 ]



Changes the default customer master key (CMK) for EBS encryption by default for your account in this Region.

AWS creates a unique AWS managed CMK in each Region for use with encryption by default. If you change the default CMK to a symmetric customer managed CMK, it is used instead of the AWS managed CMK. To reset the default CMK to the AWS managed CMK for EBS, use ResetEbsDefaultKmsKeyId . Amazon EBS does not support asymmetric CMKs.

If you delete or disable the customer managed CMK that you specified for use with encryption by default, your instances will fail to launch.

For more information, see Amazon EBS encryption in the Amazon Elastic Compute Cloud User Guide .

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.


--kms-key-id <value>
[--dry-run | --no-dry-run]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]


--kms-key-id (string)

The identifier of the AWS Key Management Service (AWS KMS) customer master key (CMK) to use for Amazon EBS encryption. If this parameter is not specified, your AWS managed CMK for EBS is used. If KmsKeyId is specified, the encrypted state must be true .

You can specify the CMK using any of the following:

  • Key ID. For example, 1234abcd-12ab-34cd-56ef-1234567890ab.

  • Key alias. For example, alias/ExampleAlias.

  • Key ARN. For example, arn:aws:kms:us-east-1:012345678910:key/1234abcd-12ab-34cd-56ef-1234567890ab.

  • Alias ARN. For example, arn:aws:kms:us-east-1:012345678910:alias/ExampleAlias.

AWS authenticates the CMK asynchronously. Therefore, if you specify an ID, alias, or ARN that is not valid, the action can appear to complete, but eventually fails.

Amazon EBS does not support asymmetric CMKs.

--dry-run | --no-dry-run (boolean)

Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is DryRunOperation . Otherwise, it is UnauthorizedOperation .

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See ‘aws help’ for descriptions of global parameters.


To set your default CMK for EBS encryption

The following modify-ebs-default-kms-key-id example sets the specified CMK as the default CMK for EBS encryption for your AWS account in the current Region.

aws ec2 modify-ebs-default-kms-key-id \
    --kms-key-id alias/my-cmk


    "KmsKeyId": "arn:aws:kms:us-west-2:123456789012:key/0ea3fef3-80a7-4778-9d8c-1c0c6EXAMPLE"


KmsKeyId -> (string)

The Amazon Resource Name (ARN) of the default CMK for encryption by default.