Create your own client certificates
Amazon IoT supports client certificates signed by other root certificate authorities (CA). You can register client certificates signed by another root CA; however, if you want the device or client to register its client certificate when it first connects to Amazon IoT, the root CA must be registered with Amazon IoT.
A CA certificate can be registered by only one account in a Region.
For more information about using X.509 certificates to support more than a few devices, see Device provisioning to review the different certificate management and provisioning options that Amazon IoT supports.