An identity is communicated by a client device to a server without requiring the identity to be disclosed to eavesdroppers and without requiring the use of symmetric or asymmetric cryptography. In one example, the identity is an identity of the client device, where the identity has been assigned to the client device by the server through the provisioning of a unique subset of client-identifying keys. In another example, the identity is an identity of a group shared secret that has been provisioned by the server to the client device.