Turn on KMS key encryption of session data (console) - AWS Systems Manager

Turn on KMS key encryption of session data (console)

Use AWS Key Management Service (AWS KMS) to create and manage encryption keys. With AWS KMS, you can control the use of encryption across a wide range of AWS services and in your applications. You can specify that session data transmitted between your managed nodes and the local machines of users in your AWS account is encrypted using KMS key encryption. (This is in addition to the TLS 1.2 encryption that AWS already provides by default.) To encrypt Session Manager session data, create a symmetric KMS key using AWS KMS.

AWS KMS encryption is available for Standard_Stream, InteractiveCommands, and NonInteractiveCommands session types. To use the option to encrypt session data using a key created in AWS KMS, version 2.3.539.0 or later of AWS Systems Manager SSM Agent must be installed on the managed node.


You must allow AWS KMS encryption in order to reset passwords on your managed nodes from the AWS Systems Manager console. For more information, see Reset a password on a managed node.

You can use a key that you created in your AWS account. You can also use a key that was created in a different AWS account. The creator of the key in a different AWS account must provide you with the permissions needed to use the key.

After you turn on KMS key encryption for your session data, both the users who start sessions and the managed nodes that they connect to must have permission to use the key. You provide permission to use the KMS key with Session Manager through AWS Identity and Access Management (IAM) policies. For information, see the following topics:

For more information about creating and managing KMS keys, see the AWS Key Management Service Developer Guide.

For information about using the AWS CLI to turn on KMS key encryption of session data in your account, see Create a Session Manager preferences document (command line) or Update Session Manager preferences (command line).


There is a charge to use KMS keys. For information, see AWS Key Management Service pricing.

To turn on KMS key encryption of session data (console)
  1. Open the AWS Systems Manager console at https://console.aws.amazon.com/systems-manager/.

  2. In the navigation pane, choose Session Manager.

  3. Choose the Preferences tab, and then choose Edit.

  4. Select the check box next to Enable KMS encryption.

  5. Do one of the following:

    • Choose the button next to Select a KMS key in my current account, then select a key from the list.


      Choose the button next to Enter a KMS key alias or KMS key ARN. Manually enter a KMS key alias for a key created in your current account, or enter the key Amazon Resource Name (ARN) for a key in another account. The following are examples:

      • Key alias: alias/my-kms-key-alias

      • Key ARN: arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-12345EXAMPLE


      Choose Create new key to create a new KMS key in your account. After you create the new key, return to the Preferences tab and select the key for encrypting session data in your account.

    For more information about sharing keys, see Allowing External AWS accounts to Access a key in the AWS Key Management Service Developer Guide.

  6. Choose Save.