KMS Alias

The AWS::KMS::Alias resource specifies a display name for a [KMS key](https://docs.aws.amazon.com/kms/latest/developerguide/concepts.html#kms_keys). You can use an alias to identify a KMS key in the KMS console, in the [DescribeKey](https://docs.aws.amazon.com/kms/latest/APIReference/API_DescribeKey.html) operation, and in [cryptographic operations](https://docs.aws.amazon.com/kms/latest/developerguide/concepts.html#cryptographic-operations), such as [Decrypt](https://docs.aws.amazon.com/kms/latest/APIReference/API_Decrypt.html) and [GenerateDataKey](https://docs.aws.amazon.com/kms/latest/APIReference/API_GenerateDataKey.html). Adding, deleting, or updating an alias can allow or deny permission to the KMS key. For details, see [ABAC for](https://docs.aws.amazon.com/kms/latest/developerguide/abac.html) in the *Developer Guide*. Using an alias to refer to a KMS key can help you simplify key management. For example, an alias in your code can be associated with different KMS keys in different AWS-Regions. For more information, see [Using aliases](https://docs.aws.amazon.com/kms/latest/developerguide/kms-alias.html) in the *Developer Guide*. When specifying an alias, observe the following rules. + Each alias is associated with one KMS key, but multiple aliases can be associated with the same KMS key. + The alias and its associated KMS key must be in the same AWS-account and Region. + The alias name must be unique in the AWS-account and Region. However, you can create aliases with the same name in different AWS-Regions. For example, you can have an alias/projectKey in multiple Regions, each of which is associated with a KMS key in its Region. + Each alias name must begin with alias/ followed by a name, such as alias/exampleKey. The alias name can contain only alphanumeric characters, forward slashes (/), underscores (_), and dashes (-). Alias names cannot begin with alias/aws/. That alias name prefix is reserved for [](https://docs.aws.amazon.com/kms/latest/developerguide/concepts.html#aws-managed-cmk). *Regions* KMS CloudFormation resources are available in all AWS-Regions in which KMS and CFN are supported.