
Does disabling Wi-Fi prevent my Android phone from sending Wi-Fi frames? [pdf] - fanf2
https://hal.inria.fr/hal-01575519/document
======
michaelt
One of my frustrations with Android is the fact Google Maps constantly bugs me
to enable "Google's Location Service". Even if I've asked for something as
simple as centering the map on my GPS location. I must have answered 'no' to
that prompt a hundred times by now.

My phone has GPS, which is privacy-preserving and more accurate when outdoors
- which is any time I'm navigating, as I don't need maps indoors. So "Google's
Location Service" is useless to me. I don't understand why Google has made it
so difficult to avoid sharing my location "anonymously" with them.

~~~
eponeponepon
What I find particularly aggravating about that is the UX dark pattern they've
utilised for the dialogue. I forget the exact wording, but rather than "Would
you like to switch on Google's location service? [Yes] [No]", it's something
like "To continue, enable Google's location service. [OK] [Cancel]" \-
implying that you need to switch it on to do what you wanted to.

~~~
moe
Not surprising.

Your lifetime value for Google multiplies when they can track your location.
They learn where you live/work, how you commute, who you hang out with,
whether and where you travel, when you get sick, etc.

Much of it can be approximated by looking at your searches alone, but the
correlation with your location record yields much higher accuracy.

~~~
r00fus
I am SOOO glad that in iOS 11 I'll be able to force apps to only get my
location data when they're running (e.g. Waze). Right now some of these apps
can get location data because they the app only presents old-style privacy
controls (all the time / not at all).

------
massel
TL;DR (from TFA): No. We show that another option, called "Always allow
scanning", when activated, makes a device send Wi-Fi frames which can be used
to track this device, even if the Wi-Fi switch is off. This option is not
clearly described in all Android versions, and sometimes even not
deactivatable. Besides, the Google Maps application prompts the user to
activate this option.

~~~
ringaroundthetx
TL;DR: No. Just from the rule of journalism about asking a question in the
title.

~~~
DC-3
In fairness, in this instance 'No' is the interesting answer.

------
jitix
A bit tangential but here's another reason to disable wifi: even if you don't
join a wifi network your phone can be tracked via the packets that it sends
out to find wifi networks. That can be used is triangulate people's location
within closed spaces like department stores. Source: I work at a company where
we sell this tech to department stores and such. We are still not allowed to
join that data with our shadow profiles of the users but that might happen in
the future.

I've become extremely privacy oriented ever since I started working here and
saw how creepily companies track users.

~~~
guelo
I don't really get the concern. Retailers also install video cameras and track
everywhere you go in their stores.

~~~
fish_fan
Yea but cameras won't show them what you bought last week, your credit, your
social network, your criminal records.

Man the possibilities for fascism only get more and more exciting for future
dictators.

~~~
jefftk
Facial recognition is getting better; cameras may well be enough to do this
soon.

------
stephenboyd
Yelp just paid 20 million dollars for Turnstyle Solutions, which specializes
in tracking retail customers with the WiFi signals sent by smartphones,
without asking for the phone customer's consent. If you want to opt out, you
have to go out of your way to register your device's mac address with them.

[https://www.wsj.com/articles/what-secrets-your-phone-is-
shar...](https://www.wsj.com/articles/what-secrets-your-phone-is-sharing-
about-you-1389663783)

[https://techcrunch.com/2017/04/04/yelp-acquires-wi-fi-
market...](https://techcrunch.com/2017/04/04/yelp-acquires-wi-fi-marketing-
company-turnstyle-analytics-for-20-million/)

~~~
agumonkey
This whole era of data gathering boggles my mind, what kind of fluff do they
extract ? and how valuable is it really ?

I think it was S. Yegge that said we turned the smartest brains into like-
button developpers. :sigh!

~~~
sixothree
> and how valuable is it really ?

at least 20 million dollars

------
r1ch
Somewhat related is positioning your WiFi AP based on passive signal strength
monitoring. Both Apple and Google do this to maintain their own private WiFi
positioning databases, but there are also public databases with this
information too. [http://find-wifi.mylnikov.org/](http://find-
wifi.mylnikov.org/) is a great example of this - I was very surprised to find
a brand new AP I'd installed less than six months ago already in the DB! I
wonder how they track it - I certainly don't expect many people to be running
their tracking apps. Perhaps there is some reporting SDK that gets bundled
with certain free apps?

The author of the above page has a WiFi positioning demo app for iPhone and
Android that uses those public databases - during my testing it was almost as
accurate as GPS (even more so indoors) with instant results.

~~~
Mister_Snuggles
If I had to guess, Apple and Google use the GPS on the phones plus the WiFi
information to feed back into those databases. It makes sense for them to do
this as it helps improve the accuracy of their location services.

~~~
pbhjpbhj
Presumably they also wardrive (war-fly with directional antennae??) when
they're making maps/streetview?

~~~
kej
No presumably about it, there was some minor outrage that they were capturing
traffic when it first happened:
[http://www.pcworld.com/article/198667/google_wifi_data_captu...](http://www.pcworld.com/article/198667/google_wifi_data_capture_unethical_but_not_illegal.html)

------
SadWebDeveloper
If you are concerned about this "privacy issue" you should try Smarter Wi-Fi
Manager from Kismet Wireless: [https://www.kismetwireless.net/android-
swm/](https://www.kismetwireless.net/android-swm/)

But in newer versions of Android (afaicr > 7.0) is no longer using an
aggressive approach (visible to other devices), it just passively collect
frames
([https://plus.google.com/+mikekershaw/posts/DmpQ2no5bEk](https://plus.google.com/+mikekershaw/posts/DmpQ2no5bEk))
so it's no longer an a privacy issue to have this option on those versions,
still would recommend SWM to increase security.

~~~
edwhitesell
My Android 7 phone still sends WiFi probes anytime I wake the screen. Even
though the power saving features are disabled such that it remains connected
while the screen is off.

There's a lot Android could do better in this area.

~~~
SadWebDeveloper
If WiFi is on this is an expected behavior; The article is referring is when
WiFi its off, haven't seen my android 7.0 launching probes on the network with
WiFi-Scanning on and WiFi off, with WiFi on it does what you are describing.

------
matt_wulfeck
Yet another reason for privacy-conscious individuals to switch to iOS and a
newer iPhone. I hate the walled-gardens as much as the next person, but
Apple's stance on privacy and security is unparalleled in today's ecosystem.

~~~
Forbo
Any indication this is still the behavior in Android 7.0 and beyond? What
about in Pixel phones? The one first-party Google device used in the study was
a Nexus S running 4.4.

~~~
SadWebDeveloper
>= 7.0 improved on these and its not longer aggressively looking for beacons,
it uses a passive approach.

------
lucb1e
[pdf]

TL;DR: when wifi is off, and the setting whose description reads "allow
scanning when wifi is off" is turned off (not all softwares have this toggle
available in the WiFi settings, it seems default-on) then it doesn't seem to
send frames.

------
nxc18
PSA: Google stores your precise location, tied to your account, for every
moment of every day. In about 1.5 years of using android regularly I generated
700,000 data points. I understand Google maps on iOS participates in this.

Go to takeout.Google.com to see what's in your personal dossier.

~~~
teddyfrozevelt
You can also go to maps.google.com/timeline for a better visual.

~~~
pjc50
Fortunately you can skip this one by never signing in to Google maps, although
you then lose the benefits of history.

Just checked and my location timeline is blank after several years of this.

~~~
pbhjpbhj
>my location timeline is blank //

The one they show you is, at least. /cynic

------
bhhaskin
There really needs to be an alternative open source mobile OS. I had really
hoped that would be Ubuntu touch, but now that development is moved over to
ubports I am not sure wide spread support is going to happen.

~~~
Freak_NL
I would go even further and say we need a free software mobile OS.

~~~
RankingMember
As long as it has a good UI. My experience has been that OSS can be
functional, but often comes with a bad UI that turns off users.

------
stephengillie
Android phones respond to ping when in airplane mode.

I have a speech bot that pings my phone (find IP by ARP) and it speaks
randomly on successful ping.

Sometimes, at night, I put my phone in airplane mode, and sometimes my bot
still speaks.

~~~
a_t48
At least in iOS-land, you can be in airplane mode and still have wifi.

~~~
tajen
Wifi isn't forbidden on planes?

~~~
Johnny555
Airlines are pushing people to use Wifi on planes by installing Wifi based
entertainment systems that display content on user devices (the airlines like
it because they save weight and money by not needing seat-back displays).

Cellular transmissions are still technically prohibited, but I bet many people
don't know how to turn on Wifi while in "airplane mode", so they don't use
airplane mode.

Here's one such system:

[https://www.united.com/web/en-
US/content/travel/inflight/ent...](https://www.united.com/web/en-
US/content/travel/inflight/entertainment/personal-device-entertainment.aspx)

~~~
kogepathic
_> Cellular transmissions are still technically prohibited_

In the US. Internationally they are permitted and several airlines offer GSM
service in flight. [0]

[0] [http://www.telegraph.co.uk/travel/news/Which-airlines-
allow-...](http://www.telegraph.co.uk/travel/news/Which-airlines-allow-in-
flight-mobile-use/)

------
tuddman
To disable that deceptive snooping in 6.0 (Marshmallow):

Settings -> Location -> Improve Accuracy -> Toggle Wi-Fi scanning.

~~~
jayess
Any idea how to do this in 7?

~~~
gcb0
google surreptitiously moved it to the ellipsis menu.

on android 7 and 7.1:

settings > location > three vertical dots on the top right > scanning.

And on this screen disable wifi and bluetooth scanning.

And, you would think that would disable wifi/bt scanning, right? wrong!

on the previous screen (settings>location), you also have to click on "mode".
And then select "Device only". If you select "high accuracy" or "battery
saving", it will ignore the wifi off on the ellipsis menu and still use it!

And there is more! ...still on the location screens, scroll down. Past the
"recent location requests" and see a section called "Location services". It
might very well include a "Qualcomm izat accelerated location". What it does?
well, nobody knows! does it enable wifi from sleep mode on the chip? it might.
it might not. again, who knows?

------
guelo
This is pretty simple and I don't think it's nefarious. Android WiFi is used
for two purposes, networking and location. The main WiFi switch toggles the
networking function and the main location switch toggles its location fuction
as well as other location providers such as GPS and cellular location. If you
want the main WiFi toggle to also affect its location function then that's
what the "Always allow scanning" setting is for.

~~~
squeaky-clean
Well apparently it's not just my phone using it to track my location. This
article convinced me to disable the always on Wi-Fi scanning.

> However, Wi-Fi scans are not only used by the device to derive its location,
> analytics companies now leverage the Wi-Fi probe requests to estimate the
> number of visitors in stores and malls and to record customer mobility.
> Indeed, by counting the number of unique MAC addresses broadcast in probe
> requests, retailers can derive the number of smartphone carriers in their
> store. Location tracking of these customers is performed by following these
> MAC addresses as they are heard by antennas located in different spots.

~~~
guelo
Both iOS and Android started randomizing WiFi Mac addresses a few years ago to
prevent that kind of tracking.

~~~
reaperducer
Then how is it possible for my iPhone to connect to my AP that has MAC
filtering enabled?

~~~
guelo
I think the MAC address randomization is only for the scanning, not
connecting.

------
otto_ortega
Does any body knows how to run a passive scan for networks in range from an
app, even if the Wi-Fi is OFF?

I know this is possible for sure, the app "Wifi Analyzer" does it. As you can
see on:

[https://snag.gy/cfYTmy.jpg](https://snag.gy/cfYTmy.jpg)

The only network related permission this app requests is "Wi-Fi connection
information" so I'm wondering how they do it, and if it is possible to do so
from a background service. I will like to run scans periodically and show up a
notification once a predefined network is in-range.

~~~
r1ch
This relates to the setting mentioned in the article, "always allow scanning".

------
tony-allan
This also occurs on Apple iPhones...

[http://www.idownloadblog.com/2016/01/21/iphone-ipad-
location...](http://www.idownloadblog.com/2016/01/21/iphone-ipad-location-
services/)

[http://www.moutfitters.com/blog/iphone-privacy-
settings/](http://www.moutfitters.com/blog/iphone-privacy-settings/)

------
shocks
Title needs a pdf tag.

------
mirimir
People concerned about such matters use devices with cellular and WiFi radio
nuked. With separate devices for cellular and WiFi radio. Connected using
shielded wires.

Edit: OK, people _greatly_ concerned do that. I don't even use the damn
things. But I know what it takes to secure them.

Edit: I note that none of my VM hosts have integrated cellular and WiFi
radios. And I seriously doubt that devices used in high-security commercial,
government and military roles have such things. Maybe not even integrated
Ethernet. Also, devices with modular cellular and WiFi radios could be
produced in the consumer sector. Maybe they'd cost more, and only sell in
niche markets, but it's doable.

------
mirekrusin
Interesting that simple UI on/off switch requires a scientific paper as proper
documentation.

------
killnine
F Droid wifi police

------
tinus_hn
Sleazy. Then again, par for the course for modern Google.

------
eighthnate
The honest answer is unless you physically disable your wifi antenna, you
can't really be sure. The same thing with your laptop web camera or anything
physical on your desktop/laptop/smartphone/etc.

If you want to be sure that your laptop camera isn't recording you, you have
to put electric tape over it, if you want to make sure your mics on your
devices aren't recording you then you have to physically block it.

[http://www.telegraph.co.uk/technology/2016/09/15/put-tape-
ov...](http://www.telegraph.co.uk/technology/2016/09/15/put-tape-over-your-
webcam-fbi-director-warns/)

This is a very complicated issue of reliability of
kernel/compilers/hardware/etc. We are dependent on these layers telling us
what "reality" is. But how reliable is it?

And interesting look into "trust".

[http://wiki.c2.com/?TheKenThompsonHack](http://wiki.c2.com/?TheKenThompsonHack)

