There are a range of factors or approaches that can be used to secure communication to IOT devices:
- Virtual Private Networks: VPNs are good as long as both points of the connection are secured. However, if one end of the VPN is compromised, then a hacker has access to the entire stream of information. If both the source and destination points of the VPN are both solid and secure, then the VPN is a fantastic way of transferring traffic in IOT.
SSL could be used, even all the way through encrypting the data before it's sent and received, attributing hash back values to the data prior to it being sent and then decoding it on your end.