Apparatus, systems, and methods may operate to establish a secure communications tunnel between a server node and a client node, and to receive user requests from the client node at the server node via the secure communications tunnel. The user requests may be received in conjunction with a device verification token derived from nonces generated by the server node and transmitted to the client node as part of keep-alive response messages. The nonces may change according to a period of time established by the server node. Additional apparatus, systems, and methods are disclosed.