back to article Drone perves defeated by tinfoil houses

If a drone-creeper is snooping on you, you could catch them by grabbing the video stream – but what if it's encrypted? Even then, detection turns out to be pretty straightforward: as researchers from Ben-Gurion University of the Negev and the Weizmann Institute of Science explain, you don't need to decrypt the stream at all, …

  1. Voland's right hand Silver badge

    They were not defeated

    1. They were not defeated. They noticed that it is filming them, but could do bugger all about it.

    2. This can be automated if you have your own CCTV, unfortunately with a relatively low confidence. If your CCTV rate goes up at the same time as a wifi transmission on a new SSID you have not seen before it is likely it is a drone and is around.

    3. Frankly, I would rather spend my time and money on a Razzie controlling two servo motors attached to a pressure washer lance. I have yet to see a consumer drone which survives a direct hit even from the most basic Karsher model. Now that is defeating.

    1. MyffyW Silver badge

      Re: They were not defeated

      Thanks @Voland - I had been planning on using a Nerf Rebelle but a pressure washer is a far better idea.

      1. Anonymous Coward
        Anonymous Coward

        Re: They were not defeated

        Be careful. A mis-aimed pressure water jet will damage flesh. It can strip the skin. Even worse it can inject water under the skin that can cause gangrene.

        1. TRT Silver badge

          Re: They were not defeated

          Vertically firing lawn sprinklers. The fog of war.

          1. CrazyOldCatMan Silver badge

            Re: They were not defeated

            The fog of war.

            Complete with house robots going on the rampage?

            (Mine's the one with a big spinner in the pocket. Thank you)

        2. Joe Harrison Silver badge

          Re: They were not defeated

          I pressure-washed my patio and took the top surface off the concrete tiles. Be careful with these things

      2. CrazyOldCatMan Silver badge

        Re: They were not defeated

        but a pressure washer is a far better idea.

        Even better would be a troupe of monkeys flinging what troupes of monkeys are famous for flinging.

        (Try saying that quickly five times!)

        1. RegGuy1
          Thumb Up

          (Try saying that quickly five times!)

          "that quickly that quickly that quickly that quickly that quickly"


    2. 080

      Re: They were not defeated

      I don't really see how you are going to upset a drone with a pressure washer since they rely on the speed of a small flow of water to blast off the dirt. As soon as the water leaves the jet the pressure is zero but the speed is quite high so the cleaning power diminishes very quickly with distance and within less than a meter you will only get a fog.

      Now, a fire hose with a 16mm nozzle at 6 Bar will do the job, if you can hold it.

      1. Voland's right hand Silver badge

        Re: They were not defeated

        I don't really see how you are going to upset

        Dunno about yours, the lance on mine is adjustable so it maintains a decent jet for a few meters on one of the settings. Even if it was not, I would have definitely made a replacement nozzle for a case like that.

        I definitely agree that it will not beat a 16mm firehose at 6 bar. Unfortunately, most domestic water supplies will not deliver that for more than a few seconds - the pressure will drop. That, in itself is also not an insurmountable obstacle. On/Off/On/Off. Nice little water machine gun (I do not envy anyone trying to take a shower at the same time though).

        End of the day, even if you do not damage it physically, just flipping the damn thing by hitting it on one side is enough. It is going down

        1. TRT Silver badge

          Re: Vertically firing lawn sprinklers...

          Also an effective deterrent for cats and children.

  2. Anonymous Coward
    Anonymous Coward

    Doh.....easy to circumvent.

    Instead of the drone using a Variable Bit Rate (VBR) codec just set it up to use Constant Bit Rate (CBR) codec and deliberately introduce some programmed 'noise' into the overscan at the top and the bottom of the video signal so it's constantly in variance regarding the data stream.

    1. TRT Silver badge

      Re: Doh.....easy to circumvent.

      Next generation of video compression encoding could be not just frame-to-frame differences, but also scene-to-scene differences. Scene 1 - film active - send changes. Scene 2 - film inactive - send changes. Scene 3 - film active - send "same as scene 1".

    2. Anonymous Coward
      Anonymous Coward

      Re: Doh.....easy to circumvent.

      Yeah, but I bet your random noise doesn't look exactly the same as the noise created by this technique though. Surely the best bet would just be to turn compression off and always send a full picture. Slow but constant.

  3. Trygve Henriksen


    Drones such as the DJI Mavic transmits constantly, even when not recording.

    All you're proving is that you're in the drone's Field of View, not that they're actively recording.

    And since the Mavic has a pretty decent camera(4K video) it could actually be quite a distance away, setting up for a overview shot of the neighbours house before they put it up for sale because they want to get away from their paranoid neighbour.

    1. imanidiot Silver badge

      If it's far away the window only covers a tiny portion of the camera's view and thus only a small increase in bit-rate is observed. Only if the drone gets sufficiently close does the bit-rate increase become large enough to be noticeable.

      1. Anonymous Coward
        Anonymous Coward

        Amalric's principle

        f it's far away the window only covers a tiny portion

        Caedite eos. Novit enim Dominus qui sunt eius.

        1. Anonymous Coward
          Anonymous Coward

          Re: Amalric's principle

          "Caedite eos. Novit enim Dominus qui sunt eius."

          A useful reminder for our times in many circumstances that verge on being witch hunts.

      2. Trygve Henriksen

        Ah, but if it's far away and maneuvering for a shot, the picture will shift and cause large changes to the image. Or there may be a car passing through its field of view.

        you need to be really certain that the change in the data stream is caused by your event. That means running the event multiple times.

        And in a counter-espionage scenario that is bad because it increases the chance that the observer catches on to what is happening.


        I bought a CO2-powered airgun with 12 round magazine.

  4. Anonymous Coward
    Anonymous Coward

    I would just make the assumption it's recording/transmitting anyway and get the hosepipe out while shouting get orf my land.

    1. Anonymous Coward Silver badge
      Paris Hilton

      But what if your hosepipe is exactly what they wanted to film?

      1. Anonymous Coward
        Anonymous Coward

        Good point, must remember to feed it though my pants and coat.

    2. Trygve Henriksen

      I have an airgun with Co2 cartridgee and 12 round magazine...

  5. Haku

    Not everyone is paranoid about spying drones.

    Mainly because most don't know the actual level of sophistication of drones or even thier existance, but I'm sure the news media will be more than happy to continue with their misinformation & paranoia over this rapidly growing hobby just to gain more page views from clickbait headlines.

    I had this friendly encounter a few weeks back: (goggles recording)

    When they eventually got to the bottom of the field where I was flying from I let them use my spare set of goggles to watch me fly like this over the field and they were emazed at it (recording from a miniature 4.5 gram 720p camera+DVR stuck on with foam tape)

    This was with a quadcopter that's 13x13x6 cm weighing 110 grams, well below any sort of registration requirement based on weight.

    1. Anonymous Coward
      Anonymous Coward

      Re: Not everyone is paranoid about spying drones.

      Erm, however (and I don't want to be a killjoy) you've flown a drone, in a road, with traffic possible, and put it on an identifiable YouTube channel.

      You may not need to register on weight, but:


      (3) The person in charge of a small unmanned aircraft must maintain direct,unaided visual contact with the aircraft sufficient to monitor its flight path in relation to other aircraft, persons, vehicles, vessels and structures for the purpose of avoiding collisions.

      Your goggles count as "aided" (and yes, there is an exception, outlined further down) :

      Then there is :

      (1) The person in charge of a small unmanned surveillance aircraft must not fly the aircraft in any of the circumstances described in paragraph (2) except in accordance with a permission issued by the CAA.

      and Para 2 includes...

      (a) over or within 150 metres of any congested area; and

      (c) within 50 metres of any vessel, vehicle or structure which is not under the control of the person in charge of the aircraft; or

      (d) subject to paragraphs (3) and (4), within 50 metres of any person.

      The use of goggles also...

      ...does not remove the requirement (in paragraph 3(b)) for the competent observer to maintain direct unaided visual contact with the SUA throughout the flight. Therefore, the SUA can only be flown up to 1,000 ft if it can still be seen sufficiently for collision avoidance purposes.

      So, caution on posting things that directly contravene the regs....

      (still cool videos though)

      1. Anonymous Coward
        Anonymous Coward

        Re: Not everyone is paranoid about spying drones.

        You also should be aware that flying over (or digging under) private property without prior permission is still trespass. People can bring charges themselves in the local civil court which can inflict up to a £2500 fine, or 6 months imprisonment. (per offense)

  6. Alan Sharkey

    And you won't hear them and see them? How many people are actually monitoring extra wifi streams anyway?

    Sounds like a solution waiting for a problem

    1. DropBear Silver badge

      I suspect this is supposed to be meant for those with "cold war" level neighbours who land their drone in a conveniently covert spot to monitor you continuously (a drone in flight wouldn't last long enough for much any meaningful "surveillance", and the inherent constant motion in its picture would defeat this "attack" anyway). Which means the classic adage applies: you're either a military site if you worry about this sort of thing, or else you really, really, REALLY worry about the wrong issue because you have an incomparably larger one.

      1. Trygve Henriksen

        I'm pretty certain that people who run that kind of operation can afford drones with directional antennas.

        Every spy shop is aware of 'sidechannel' attacks and will have at least some defenses against them.

        That was pretty much explained to them when they learned that you could pick up transmissions from an unshielded monitor and cable.

    2. tim292stro

      > How many people are actually monitoring extra wifi streams anyway?

      Depends on the person and their circumstances. I live in an apartment over a coffee shop and a restaurant. After my wireless internet slowed down, I started looking at my AP's access table - I found a few devices that didn't belong, and I had WPA2 (but no RADIUS or equivalent). So I added two more commercial APs, wrote a tool to take the RSSI from each antenna and triangulate the location of the radio into a 3D volume (in addition to the other network hardening I did). I found that the tables outside the coffee shop were getting used by a local geek to try his circumvention tools. I retooled my network routing/partitioning to isolate him, making him think he was getting on "free" (stolen) WiFi as usual then redirected every outgoing request to a local copy of:

      That slowed him down for a day or two, so after that I, had my wife record "HEY!! ARE YOU WATCHING PORN?!?!?!" and I play that audio file in embedded in my warning page now for every client that shows up outside my apartment volume. Haven't seen that 90's silver VW Golf or the heavy-set unshaven guy who drove it and sat outside the coffee shop with his laptop in a while now...

      But, I did recently see in the logs a WiFi AP appear airborne across the street from me, at the city park - where it's illegal by city ordinance to fly a drone...

      Point is, just because YOU aren't watching the extra streams, don't assume nobody else in the world is or that there isn't a good reason in general for people to be doing that at all.

  7. Empire of the Pussycat

    not as good as the old thunderbirds camera detector

    but it made me think of it, and lady penelope too

    so not all bad

  8. David Roberts Silver badge
    Black Helicopters

    Water based interception

    A few hosepipe and pressure washer fans here.

    Probably OK for a very near approach over a large tract of land you own, but anywhere suburban and the main result will be shooting water onto your neighbour's property. Possibly onto your neighbour.

    You could always fly your own defence drone over your property (leading to aerial robot wars) but again anywhere suburban this is likely to be illegal (at least in the UK).

    1. allthecoolshortnamesweretaken Silver badge

      Re: Water based interception

      Ice cube cannon?

      1. Anonymous Coward
        Anonymous Coward

        Re: Water based interception

        Ice cubes + catapult = quiet, deadly (assuming you've practiced enough) & maybe untraceable.

        1. Anonymous Coward
          Anonymous Coward

          Re: Water based interception

          Use to do this with frozen gooseberries as a kid (bells outside people front doors was a favorite target). The birds would eat the evidence.

      2. Anonymous Coward
        Anonymous Coward

        Re: Water based interception

        Ice cube cannon

        Cannon no. Now a slingshot... That has a considerable appeal...

    2. CrazyOldCatMan Silver badge

      Re: Water based interception

      You could always fly your own defence drone over your property

      I'd rather have a set of defense turrets a-la Death Star. Even better if they can actually hit what they are aiming at..

  9. werdsmith Silver badge

    I'm always amazed at how people manage to covertly snoop with a thing that sounds like 10,000 angry wasps. The view of the house in this video is about the same as you can see on Google Earth Pro anyway.

    A drone operator was round these offices before christmas doing a survey of the building rooftops and nobody would rest until they could see where the weird noise was coming from, drones are about the most useless covert surveillance device possible.

    1. Anonymous Coward
      Anonymous Coward

      Until someone figures out how to jail break the imprisoned wasps in the motors & props, covert stealth drones will only be a thing you'll see in sci-fi films.

      The other major factor regarding using them as surveillance is the weather - wind & rain are not a drone's best friend, there are lots of days we can't fly outside in the UK :(

    2. Trygve Henriksen

      Not all small drones are noisy...

      The Black Hornet is pretty quiet.

      1. This post has been deleted by its author

  10. handleoclast Silver badge

    It's been done before

    They had it in Thunderbirds.

    Not only that, the Thunderbirds device could tell if it was being photographed by film cameras.

    1. Mark 85 Silver badge

      Re: It's been done before

      I was thinking "Blue Thunder ".

  11. Anonymous Coward
    Anonymous Coward

    I use frogs for defense.

    My roof is lined with mutant frogs that watch for anything flying within range then lash out a sticky tongue to snag it from the air. The frogs think it's a tasty snack & are thus more interested, provoked, & adept at making sure they nail the little bastards. If your drone gets within a kilometer of my roof then my mutant frogs will happily chew on its corpse.

    Now if you'll excuse me it's time for my medication from the nice young men in their clean white coats!

    1. CrazyOldCatMan Silver badge

      Re: I use frogs for defense.

      time for my medication from the nice young men

      Let me guess - frog pills? After all, you already have the required ingredients..

      1. Anonymous Coward
        Anonymous Coward

        Re: I use frogs for defense.

        Yes I use real frogs in my frog pills, specificly the frogs that prove unable to catch the drones!

        /wanders off muttering incoherently about eels in my hovercraft...

  12. Anonymous Coward
    Anonymous Coward

    410 Shotgun is your friend :)

    Bang Bang, Bye Bye

    1. Andy Miller

      Re: 410 Shotgun is your friend :)

      410 Gone

    2. Potemkine! Silver badge

      Re: 410 Shotgun is your friend :)

      Problem of firing upwards is that unless the ammo reaches satellization velocity it will tend to come backwards, possibly on an innocent bystander...

      1. Swarthy Silver badge

        Re: 410 Shotgun is your friend :)

        For a rifle, or a slug, that is correct, but with a shotgun (especially with smaller shot), the terminal velocity is far below a terminal velocity for the mass.

  13. ThatOne Bronze badge

    Arm Laser Turrets!

    Shooting a drone down (one way or another) is dangerous and breaks the law (potentially several laws).

    So, what about blinding it with a laser? Obviously not a tiny 0.2W laser pointer, I'm thinking about something a little beefier.

    Shining it on the camera lens should blind the camera somewhat, wouldn't it? And if you don't use a laser strong enough to actually damage the camera, there is nothing anybody could sue you about; AFAIK there is no law against shining lasers on drones hovering over your garden.

    (Now to devise a targeting system to keep the laser on target despite the drone's constant jerky movements.)

    1. tim292stro

      Re: Arm Laser Turrets!

      > "...And if you don't use a laser strong enough to actually damage the camera, there is nothing anybody could sue you about; AFAIK there is no law against shining lasers on drones hovering over your garden..."

      With people's luck today, the dazzler laser would have enough range to point at a passing jumbo jet - pretty sure that's illegal. Most people who aren't trained to shoot guns around people aren't aware of the concept of ballistic backdrop... ;-)

      1. Haku

        Re: Arm Laser Turrets!

        "the concept of ballistic backdrop"

        When watching Star Wars etc. I do sometimes wonder in the space battle scenes where all those stray laser blasts end up...

        1. Aqua Marina Silver badge

          Re: Arm Laser Turrets!

          In the old original X wing PC game, you could come to a complete stop, divert all power to engines, fire a laser then go full throttle and catch it up. After 30 seconds or so the laser bolt just disappeared. I assume the game is based on real physics!

  14. Potemkine! Silver badge


    I've got a project to sell: to protect your privacy, buy a drone killerz (TM) ! This defense drone is specially designed to eradicate any threat above a specific area. Equipped with R/F detection and visual sensors, it can detect any drone over your house and disable it by several means: net throwing, rotating blades... It can even hook the peeping drone and bring it back to you!

    For the small amount of $999, you can buy already one! First deliveries expected in 2027. Anyone interested?

    1. Haku

      Re: Crow(d)funding

      "First deliveries expected in 2027."

      Will they be delivered by drone?

  15. tim292stro

    If your house has SmartGlass on it, why not take the time to actually detect the drone, and then automatically opaque the windows?

    Seems like a few upwards facing cameras with very wide angle lenses and an electronic iris, should be able to detect a drone or birds - and classify if the object is loitering or flying past for simple classification. Then piggy back that with some SDR radio direction finding (, and you should be able to further pick out if that "bird" is emitting radio waves...

  16. Garymrrsn

    Counter Measure?

    A miscreant could figure out how to add dummy bits to the transmit stream to smooth the bit rate and make it appear to be a continuous stream.

    It would be technically difficult and expensive but not out of the range of possibility for a government or well heeled corporation.

  17. Captain Obvious


    There would be a huge market for these (shirts that could tell when being spied on) in the Middle East, ISIL, etc.

  18. Muscleguy Silver badge

    Instead of wearing flashing LEDs you could just walk about or run or wave your arms about. It's fascinating how geeks ALWAYS seek the techno solution when there are plenty of meatspace alternatives.

    1. Phukov Andigh Bronze badge

      thats because you cannot effectively monetize or sell non hardware solutions. Not much geekery when there's a product to be sold, its marketing in the front and the "this would be cool" techies in the back

  19. Phukov Andigh Bronze badge

    this is why

    this is why you should never use WiFi for FPV. 5.7ghz or go home :)

  20. cortland

    It's possible

    It's possible that a receiver able to demodulate these frequencies might allow confirmation by listening to its audio output. And yes, I own a few.

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