Monitoring Home Power Consumption for less than $25 • Hacker News Board

Re: Monitoring Home Power Consumption for less than $25

#101

Post by SergeAx » Sat, Dec 30, 2017, 4:28 PM UTC

zzzcpan wrote: post #98

SergeAx wrote: post #49

It is extremely strange they don't use even primitive encryption. I work for Russian company "Strizh Telematics", we are making smart resource meters. We take security very seriously here: all transmits are encrypted with 64 bit keys and data protocols are specifically protected from statistical and repeat-packet attacks.

I'm curious, if someone finds a vulnerability in your algorithms somewhere, will you be able to quickly deploy updates to all the installed smart meters? Because, honestly, "taking security very seriously" doesn't mean anything anymore.

Everyone knows that in "IoT" letter "S" means "security" :) We do have an ability to burn updated firmware for most of the devices on premises using special hardware pieces, similar to ones used by factory staff. For less complicated devices we can just replace microcontroller modules, and reuse old ones later. That would be quite expensive, but we'll live. I heard there's some sort of insurance contract for that matter.

Re: Monitoring Home Power Consumption for less than $25

#102

Post by kasey_junk » Sat, Dec 30, 2017, 4:45 PM UTC

JohnMort wrote: post #27

masklinn wrote: post #19

> Some research told me that the power company accomplishes this via a simple radio broadcast on the 900Mhz spectrum. Interesting. Around here (mainland Europe) they're currently installing "smart" meters which do this using CPL rather than radio. > And with one simple command, I was reading the power (and probably water) meters for my entire neighborhood That is a bit troubling from a physical security perspective,…

What about thieves going around selecting data and pinpointing the house the one with the least consumption so they can find out if you are absent or not. Incredible techonology

It is much easier and more accurate to go to a house and just look to see if anyone is home.

Plus you’ll see dogs/locks/neighbors which are the actual important things...

Re: Monitoring Home Power Consumption for less than $25

#103

Post by myrandomcomment » Sat, Dec 30, 2017, 4:59 PM UTC

My first thought was this is cool. Second, I should do this also. Third, hey I can just login to PGE and see this data already, dang it, abort. :) They cannot keep the power on in the slightest wind storm, but at least I know how much power I am not using at that time.

Re: Monitoring Home Power Consumption for less than $25

#104

Post by pbhjpbhj » Sat, Dec 30, 2017, 5:03 PM UTC

emilburzo wrote: post #63

alkonaut wrote: post #61

Earlier quoted context omitted.

No, the meter is sealed, which is the benefit of this type of arrangement. The meter just sits attached to the meter on the outside, so it's obvious that nothing is tampered with. Many power companies even sell their own (branded) kits that does this. It's also very rare to have someone come read the meter. Like all other parts of society anything that can be automated at almost any cost has been already. I have had…

> I have had no one read water or power meters for many years. Ah, that makes more sense now :) Over here we still have people that come to read the meters every 3 months.

In the UK they use estimated readings, primarily it seems as a way to borrow a pretty large amount from their customers - they appear to "estimate" at 20% above actual rates. Evil, but pretty clever.

Re: Monitoring Home Power Consumption for less than $25

#105

Post by glogla » Sat, Dec 30, 2017, 5:07 PM UTC

SergeAx wrote: post #81

orf wrote: post #79

Earlier quoted context omitted.

Still, the comment above still stands. Not sure about the key bruteforcing estimates, surely a couple of days of readings would be enough. Are the keys stored on the devices? Is it a shared key?

Every device has it's own unique keys - one for transmitting data and another for receiving commands. They are burned with firmware in production. If you are interested in bruteforcing - I can send you two weeks worth of my home water meters' data packets to play with :) See, the CRC is calculated for encrypted data, so there is no way to know if the guessed key is correct.

No MACs?

Re: Monitoring Home Power Consumption for less than $25

#106

Post by masklinn » Sat, Dec 30, 2017, 5:27 PM UTC

jdavis703 wrote: post #97

Heliosmaster wrote: post #42

Earlier quoted context omitted.

You just need to build a baseline: hide a device and record activity over a long-ish period of time and then it's easier to sense patterns

Unless your house has something very valuable, I kind of doubt most thieves would spend this much time plotting to break in.

They don't need to spend any time on it past the initial setup, you can have an automated system integrating the consumption pattern of an entire neighbourhood, and pointing out which owners are likely on holidays.

Re: Monitoring Home Power Consumption for less than $25

#107

Post by lucaspiller » Sat, Dec 30, 2017, 5:49 PM UTC

ris wrote: post #85

SergeAx wrote: post #77

Earlier quoted context omitted.

Our most talkative meters are currently broadcasting 4 packets of data per hour. Water meters with autonomous power are limited to one or two (for central hot water supply) packets per day. With all the randomness added collecting data for successful key bruteforcing will take months or even years. On the other hand, using 64 bits allows us to use 16- or even 8-bit microcontrollers, which is beneficial to power consu…

> Of four recources commonly metered in Russia - electricity, water, gas and heat When you say "heat" - is this steam from a combined heat & power plant? I was aware these were quite widespread in Russia but didn't know they were metered.

It's fairly common in eastern and northern Europe too. In my building there is a single heat pipe from the city, however each unit has it's own meter for cold water, hot water (for taps) and hot water (for heating). The hot water meters are different in that the first measures the water flow, and the later measures the heat flow.

Re: Monitoring Home Power Consumption for less than $25

#108

Post by SergeAx » Sat, Dec 30, 2017, 6:00 PM UTC

glogla wrote: post #105

SergeAx wrote: post #81

Earlier quoted context omitted.

Every device has it's own unique keys - one for transmitting data and another for receiving commands. They are burned with firmware in production. If you are interested in bruteforcing - I can send you two weeks worth of my home water meters' data packets to play with :) See, the CRC is calculated for encrypted data, so there is no way to know if the guessed key is correct.

No MACs?

There are unique device Ids, they kinda like MACs.

Re: Monitoring Home Power Consumption for less than $25

#109

Post by dylan604 » Sat, Dec 30, 2017, 6:09 PM UTC

dmateos wrote: post #58

Useful for finding the 12/12 or 18/6 pattern spikes of a weed grow house also.. `

on a 12/12 cycle, why not split the crop in half with offset cycles? or on the 18/6, split into thirds, so that only 1/3 is off? then it would be an even/constant use of power. no obvious pattern at that point.

Re: Monitoring Home Power Consumption for less than $25

#110

Post by ascorbic » Sat, Dec 30, 2017, 6:22 PM UTC

cjrp wrote: post #33

ascorbic wrote: post #28

Earlier quoted context omitted.

There's no way to tie the signal to a specific house without the serial number or a reading.

Monitor the usage and look for a change? E.g. I see the person come home and turn on their lights, whichever meter shows an increase at that time is theirs.

If you're doing that, why bother with the meter at all?