Spiped solves a different problem than this does. Spiped will allow you to obscure the existence of a certain service, as well as prevent unauthorized access to that service. But it will not allow you to hide an entire host. Tunnelling a service over spiped will simply mean that spiped appears in your portscan instead of that service.

This proposal, on the other hand, will allow you to prevent a service from being visible altogether to those without the key. Combined with spiped or a similar tunnelling scheme, this would allow you to have no visible ports on your portscan. Thus, those without the key would not even know that the host exists.