xksProxyConnectivity

Indicates how KMS communicates with the external key store proxy. This parameter is required for custom key stores with a CustomKeyStoreType of EXTERNAL_KEY_STORE.

If the external key store proxy uses a public endpoint, specify PUBLIC_ENDPOINT. If the external key store proxy uses a Amazon VPC endpoint service for communication with KMS, specify VPC_ENDPOINT_SERVICE. For help making this choice, see Choosing a connectivity option in the Key Management Service Developer Guide.

An Amazon VPC endpoint service keeps your communication with KMS in a private address space entirely within Amazon Web Services, but it requires more configuration, including establishing a Amazon VPC with multiple subnets, a VPC endpoint service, a network load balancer, and a verified private DNS name. A public endpoint is simpler to set up, but it might be slower and might not fulfill your security requirements. You might consider testing with a public endpoint, and then establishing a VPC endpoint service for production tasks. Note that this choice does not determine the location of the external key store proxy. Even if you choose a VPC endpoint service, the proxy can be hosted within the VPC or outside of Amazon Web Services such as in your corporate data center.