Couple of approaches you can take, endpoint based - cooking security into the device whether it's hardware assisted etc or network based. My inkling is on network based controls, IoT/IoE devices will touch the network somewhere, whether it's wireless, wired. I think we've lost the battle for the endpoint aspect already, early IoT/IoE devices either don't have enough grunt for certificates/encryption/whitelistibg or due to cost, are configured without security in mind. Also the plethora of different manufacturers and type of devices make it difficult to standardize.