1st line of defense is my old smartphone - metered network guarantees Homey isolation

EricV

All,
recent news about hacking of home devices ignited the following idea to insulate Homey from the Internet.
I am a newbee to Homey. do not even own one yet. I want to purchase one if I am convinced that Homey can isolate its own network properly.
My assumption is that Homey is connected to my main Wi-Fi network. The router is then connected to the I-providers network. this setup apparently has the risk that my smart devices are to be hacked (?).  Imagine my smart locks and webcams to be hacked. it causes me to abandon my hobby of a smart home.
My idea is now to use my old (Windows Mobile) as my Internet gateway to the 4G network.
There is not much data traffic so my prepaid sim card will be sufficient in the smartphone. I expect not more that 100-200 MB per month(?) usage.
I turn on the hotspot function in my smartphone and there I have my mobile Internet connection. With reduced risk of being hacked.  I tried this setup with my PC's and it works obviously flawlessly for the PC's. Iexpect the same for the homey. 
Smart idea or is there a flaw in my proposal and you think I am overprotective?

Another question is: how can I detect if my smart devices are being hacked?

Appreciate your hints and tips. -Eric

mruiter

First tip. relax and eont worry that much. security and hacking iot is hyped just like the latest intel bugs in the chips.. 
But if you realy want to isolate homey do it with filter / firewall rules in youre router. i expect you dont have a cheap tplink or fritzvullis boxy because thise are real iot hazards.

you must also create filter rules and static ip adresses on all other ip based devices you want to control with homey. 

For instance sonos ,  smart meter dongles , alarm , nest , bla bla.
If you have time to spare... good luck..

Otherwise just relax...
And the athom team is prety keen on security

EricV

Thanks. That's what I wanted to learn.