> I presume you're meaning the HAN that the meter uses to update the in home display. As far as I'm aware this is securely encrypted. Whether it'll stand the te

> I presume you're meaning the HAN that the meter uses to update the in home display. As far as I'm aware this is securely encrypted. Whether it'll stand the test of time who knows (let's face it WEP and friends certainly didn't), but the same logic could be applied to the WiFi network your router is creating. Yup, I do mean the HAN - and the way CAD including IHD connect to it. It may be based on ZigBee, but it modifies the protocol to add its own authorisation and encryption prototypes. They may have sound basis as of today but given the precedent (GSM/UMTS encryption, WEP, WPA, but also Infineon cryptographic corprocessor failures), the custom modifications to ZigBee and a couple of other deviations from usual practices I would consider it almost a certainty that within the lifetime of the device the protocol will be broken or bypassed. The question is how and when, not if. Let me put it this way: I would be pleasantly surprised if it is otherwise, as that would be the exception, not the rule. > Difference being that the data going over the HAN is likely to be a constant stream of values meaning it doesn't leak much information unless you can decrypt it. Someone able to passively observe that local network can almost certainly observe your WiFi transmissions, which will be much more variable - little to no activity when you aren't home, and lots of activity when you're streaming a movie. Most of the equipment I have is wired (optical or copper), including supposedly mobile devices ([0]) and the ones that aren't are not a good indicator of presence (roughly constant data stream). It's a different story if one was to bring an IMSI catcher, of course - but there is only so much you can do and still participate in the modern world. As a side note: I admit I may be biased as the meter location would preclude any IHD from being in range of HAN (5 reinforced concrete slabs away for electric, worse for gas), has problems with GSM connectivity for the same reasons and has dubious physical security against anyone who posseses a high tech tool known as "screwdriver" or "knife". The fallback procedure that UK suppliers have for this situation is "read the meter like a dumb meter" [sic!] until the supposed "alternative HAN solution" is in place. I know it puts me in the 3.5% minority of households, but still it rankles. [0] This is normally where I go on a rant about flagship Pixel USB-C powered phones being unable to charge and use network adapter at the same time due to incomplete implementation on the phone side - one or the other. Older micro-usb models could do both as long USB-OTG was supported. iOS devices have no such issue, but they have other ones.