
Hong Kong protestors using Bridgefy's Bluetooth-based mesh network messaging app - rmason
https://www.forbes.com/sites/johnkoetsier/2019/09/02/hong-kong-protestors-using-mesh-messaging-app-china-cant-block-usage-up-3685/#382a2076135a
======
dragonsh
No closed source mesh networking can be secure. However good user experience
it has. They are no different than using WhatsApp. Indeed in that respect at
least Signal is better.

I am not sure why protestors did not adopt the open source serval mesh project
apk and ios app. [1]

In Hong Kong given the density of building it's bit hard to have a line of
sight, so it will still be hard to build a local network. But it's still
possible to build a completely wireless network over the top of the buildings
to communicate with each other.

This communications can be blocked, but then it will still work if enough
people switch on their mobile phone and WiFi router to communicate with each
other over peer to peer network which is a combination of wired and wireless.
[2] [3] [4] [5] [6]

[1] [http://www.servalproject.org/](http://www.servalproject.org/)

[2] [https://ssbc.github.io/scuttlebutt-protocol-
guide/](https://ssbc.github.io/scuttlebutt-protocol-guide/)

[3] [https://dat.foundation/](https://dat.foundation/)

[4] [http://subnodes.org/](http://subnodes.org/)

[5] [https://hyperboria.net/](https://hyperboria.net/)

[6] [http://www.servalproject.org/](http://www.servalproject.org/)

~~~
imvetri
Something works, it helps their protests admist disruption of telecom.
Appreciate that please. Not everything needs to be technical. More we speak of
tech, more morale we loose.

~~~
GuiA
We can support what works today, while commenting on its shortfalls to raise
awareness and build better, more secure solutions for tomorrow.

~~~
imvetri
Kill snake by its head. Which is the snake in this world ?

~~~
GuiA
Rich people.

------
bitcurious
I just tried the app via the US App Store and it requires you to verify
through SMS before use. This means that it’s neither anonymous nor fit for use
in a disaster zone.

Good example of software that would be better if open source.

~~~
goatsi
For an open source, anonymous version of this check out the Briar Project:
[https://briarproject.org/how-it-works/](https://briarproject.org/how-it-
works/)

~~~
computerfriend
Briar is definitely far superior. However, one major drawback is that it is
not cross platform. This alone means it won't gain traction in the Hong Kong
protests, unfortunately.

------
frisco
Super interesting. At Burning Man this year it seemed like a significant
percent of the city had goTennas, which had never been true before. I also
remember reading about a big mesh in Brooklyn being a thing recently. I bet
we’re going to be hearing more about practical mesh networks in the coming
years.

~~~
mintplant
Reminds me of Nintendo's PictoChat, a peer-to-peer, physical proximity-based
chat application that was built into the DS. I've written about it on here
before [0]:

> [You could] chat on one of four available channels with nearby users over
> local wireless, by exchanging text and hand-drawn pictures.

> At about the peak of its popularity—right before smartphones became truly
> prevalent among kids my age—I was doing middle school science fairs. This
> involved lots of standing around waiting in front of your trifold
> posterboard while judges slowly worked their way along the rows and rows of
> other projects. We weren't supposed to leave our own stations in the
> meantime, and they were spaced out enough to make talking with your
> neighbors inconvenient. Instead, the whole room was on PictoChat, filling up
> all four channels with streams of chatter and doodles and mutual
> commiseration on our anxieties over presenting to the judges.

For a company known for perpetually trailing behind its competitors in online
services, Nintendo was oddly ahead of its time here (and with the Download
Play feature, too: peer-to-peer software distribution and wireless
networking!).

[0]
[https://news.ycombinator.com/item?id=20106929](https://news.ycombinator.com/item?id=20106929)

~~~
cwyers
I think a few things hampered Nintendo. Their (laudable) commitment to
backwards compatibility led to them getting stuck behind the curve
technologically -- the POWER architecture they stuck with from GameCube (when
it was a mostly mainstream choice) to WiiU (when it really wasn't) and the
older pre-Cortex ARM designs they were using in the 3DS years after Cortex was
shipping left Nintendo of the position of not being able to really ride the
bulk of the improvements happening in the marketplace. (It's notable that the
Switch is an abandonment of hardware-based backwards compatibility in favor of
Nvidia internals that wouldn't look out of place in an Android tablet.)

And because Nintendo prides themselves on being a family company, in much the
way that Disney does, they had less of a tolerance for looking the other way
at just how bad other users can be. Microsoft would just throw out an "Online
interactions not ESRB rated" warning and moderate the worst of it after the
fact when building Xbox Live. I don't think Nintendo ever saw that as an
acceptable option.

------
m-p-3
I find the idea interesting, but is there some kind of open-source alternative
that would be available on F-Droid?

This would be extremely useful since you can share your F-Droid archive over
bluetooth, and that would also allow the app to be distributed the same way.

One less way for the authorities to block the app from being acquired.

~~~
barbs
People have been talking about Briar in another comment thread:

[https://briarproject.org/how-it-works/](https://briarproject.org/how-it-
works/)

Seems to be available on F-Droid, but unfortunately is not cross-platform.

------
ukd1
The Bridgify ToS are egregious; under "Messaging Content", you grant them
irrevocable rights to use your messaging content...

~~~
whoopdedo
Are there many services that don't ask for this broad scope? I see it often
and understand it comes from lawyers studying the business process and writing
a contract that enables it within the Kafkaesque copyright laws. They ask for
universal copying right because if you spin up a new VM you don't want to have
to ask if every message you send to it has permission to be copied to this new
instance. And they want it to be irrevocable because you store backups for
three years and don't want to have to be constantly scrubbing them for deleted
accounts.

~~~
jorgeribs
That's exactly why, whoopdedo :)

------
jorgeribs
Hi everybody, I'm Jorge, founder of Bridgefy. Happy to answer any questions!

~~~
rcach001
Hi Jorge, fyi I just browsed for Bridgefy on google and clicked on the first
link that showed up and some random page turned up. It looked like it was
hacked or something.

~~~
frittig
That happened to me as well. Can anyone explain to me how that works? Is there
entire site hacked, but only triggered when coming from Google? Or does it
work some other way?

------
aficiomaquinas
I met the founder, Jorge Ribs, a couple of times. He gave me some of the best
advices I've received about Silicon Valley. Great guy. I'm happy it's gaining
traction!

~~~
aantix
What was the advice?

~~~
aficiomaquinas
He introduced me to the SV culture and compared it with Latin American culture
(We're both Latin American). Gave me examples I could relate to and practical
advice on how to work with Americans. Introduced me to a couple of lawyers and
some other persons. Explained me my options regarding raising venture capital
in the Valley (in the end I wasn't ready for raising).

------
hkai
To be fair, China doesn't block access to any websites in Hong Kong. In a
sense, it's a freer internet than in the US (zero sites blocked, plus piracy
is allowed).

~~~
reaperducer
At this moment. There was a piece posted to HN last week that Hong Kong's ISPs
have been asked, or fear being asked, to implement a firewall similar to
China's.

Hong Kong's ISP association published a public letter of protest about it.

Edit: Found it - [https://www.hkispa.org.hk/139-urgent-statement-of-hkispa-
on-...](https://www.hkispa.org.hk/139-urgent-statement-of-hkispa-on-selective-
blocking-of-internet-services.html)

~~~
woutr_be
That’s not entirely true. Their response came after a lot of outrage and fear
by the general population.

This outrage came after some top pro-Beijing politicians said that declaring
an emergency situation is still on the table, by doing so, it would allow the
government to block certain internet services.

Pro-Beijing politicians always use harsh language. The same way PLA officers
hinted that the PLA could be deployed in HK if requested by the government.

------
randaouser
I overcame TDMA problems associated with mesh broadcast networks by moving
channel allocation logic into the application layer. For me it was more
important for reliable delivery then bandwidth. We use geo spatial TDMA to
further allocate the channel, two proximity peers would have vastly different
time slots. Unfortunately this leaks location data (though most 2GHz channels
will). Besides wifi + bluetooth channels, we have leveraged acoustic channels
(more so for unidirectional communication from a watch tower to all peers
within an ultrasonic range)

------
enjoyyourlife
This reminds me of FireChat which was heavily used during the 2014 Hong Kong
protests

~~~
throwaway1997
We tried to use it this year but it got overloaded on the first day.

------
rmason
Using technology to bring down tyrants. The CIA should do something useful for
a change and see this app is distributed to places like North Korea, Zimbabwe,
Syria, Myanmar and Iran.

~~~
rolph
there are a number of mesh apps available they are just not promoted
mainstream as they are problematic to monetize and undercut current chat
platforms

~~~
rmason
I know of a few mesh apps. But what's significant about this one is the
protesters self selected it.

Dictators can cut off social media apps, even cut of Internet access. But they
risk turning more people out in the streets if they cut the power.

~~~
rolph
interesting that mentioning mesh and the problems of adopting it for anything
but philanthropism is not considered valid by some. Yes there was a group
consensus that a mesh was needed to communicate as a workaround to internet
blockades, the only next step now would be to jam whatever the equivalent of
802.11* is over there. I seriously wish them best of luck, thats all i can
hope for from here. Cutting the power would be exactly the thing that
escalates it from NotMyProblem to now its affecting me

~~~
petre
They don't need to jam the signal. It easier to infiltrate agents broadcasting
phony messages among the protesters, creating confusion.

------
zawerf
Does anyone have good technical resources on how mesh networks work?

Who's the authority on the identity of a recipient? Do you exchange something
out of band (for example a QR code) first? How do messages get routed? How do
messages behave under constant network partitioning and healing? Does it use
your GPS location for network topology purposes? etc etc

~~~
rolph
have a look at these:

[https://en.wikipedia.org/wiki/B.A.T.M.A.N](https://en.wikipedia.org/wiki/B.A.T.M.A.N).

[https://www.open-mesh.org/projects/open-mesh/wiki](https://www.open-
mesh.org/projects/open-mesh/wiki)

[https://kb.datto.com/hc/en-
us/articles/360024059951-Legacy-O...](https://kb.datto.com/hc/en-
us/articles/360024059951-Legacy-Open-Mesh-Open-Mesh-development-information)

[http://developer.servalproject.org/dokuwiki/doku.php?id=cont...](http://developer.servalproject.org/dokuwiki/doku.php?id=content:servalmesh:development)

there is also an open mesh for routers if you have the hardware and propensity
look at openWRT and find a mesh add on for it find out what routers you have
available to flash it onto and then you will have a MESH node.

~~~
thw0rted
Do you know of any good resources talking about considerations for handling
adversarial nodes in these networks? For example, what's to stop a rogue
implementation from advertising that it has a low cost / short distance to
every other node it's ever seen, reporting that data has been sent
successfully that actually wasn't, etc? These links give some good background
but I haven't seen anything on there about trust in a hostile environment.

------
isaack
@Jorge - is there a way for me to build "relays" out of ESP32/RPi Zero?

@HN Crowd - is there something I could do to prepare for possible censorship?
I was thinking of mesh Internet over the air, something like DN42 but over
wireless links

~~~
alexisread
You can do mesh networking with the esp32:
[https://www.espressif.com/en/products/software/esp-
mesh/over...](https://www.espressif.com/en/products/software/esp-
mesh/overview)

I think that it might be possible to adjust the app to accommodate the esp32
mesh using the mesh security to identify it. Obv. not had time to look at the
details, but you could start with this and the bridgefy SDK?

[https://medium.com/bridgefy/creating-an-offline-messaging-
ap...](https://medium.com/bridgefy/creating-an-offline-messaging-app-with-the-
bridgefy-sdk-3940ee4e8b16)

------
secfirstmd
They are also using Umbrella App, a free open source app to help protesters
learn about and manage digital and physical security.

Links: www.secfirst.org

iOS: [https://itunes.apple.com/us/app/umbrella-
security/id14537153...](https://itunes.apple.com/us/app/umbrella-
security/id1453715310)

Android:
[https://play.google.com/store/apps/details?id=org.secfirst.u...](https://play.google.com/store/apps/details?id=org.secfirst.umbrella)

------
klingonopera
If worst comes to worst, I hope there's satellite connectivity to HK. Or
landlines not under Chinese jurisdiction.

EDIT: To clarify, I'm concerned about what could happen if China cuts HK off
from the Internet.

~~~
throwaway1997
China can't cut HK off from the internet. Almost all Chinese internet traffic
is routed through Hong Kong, not the other way around.

~~~
fiblye
I don’t think China would care about cutting themselves off from the global
internet.

~~~
afterburner
Maybe the Chinese government wouldn't, but the people would care, a lot. The
Chinese government is perpetually afraid of revolution and rebellion.

~~~
klingonopera
Do mainland Chinese really use that much of the global Internet?

~~~
anigbrowl
Foreign trade is ~37% of China's GDP so probably at least 1/3 of the country
depends on it directly or indirectly. For context that's equivalent to the
entire population of the US even if only a small fraction of those people are
conducting the actual communications, negotiations, and transactions of
international commerce.

------
jonplackett
How hard would it be for the secret service to infiltrate this? If messages
are being passed back and forth could they intercept, modify etc?

------
pgt
Innovation in radio and communication used to be driven by wars and big
government contracts. Now, progress in communication technology is driven by
dissent.

------
stefek99
[https://genesis.re/comms](https://genesis.re/comms) \- help me grow this
guide!

------
hos234
How is it safe? I doubt its complicated to figure out which nodes are
broadcasting/unicasting the most frequently, without looking at the content if
you have cops at every block logging bluetooth traffic.

What's interesting is how quickly China has reacted to all this, in terms of
pumping massive disinformation onto Twitter/Facebook/Youtube. There have to be
upper limits on scaling that capability. And that is where China's weakness
lies. The more they scale their Stasi bullshit the more likely we see a
Chinese Snowden/Manning sooner or later.

~~~
rmason
It's encrypted and the only information it gives up, only when you do a system
wide broadcast, is the broadcasters phone number. So the leaders use burner
phones and the problem is solved.

What's important compared to other apps is that the protesters self selected
it. If the US government were to provide some funding the next step would to
build higher powered repeaters that can be placed on top of tall buildings.
Can you imagine a city wide communication system for pro-Democracy forces in
Hong Kong or Teheran?

~~~
dbcurtis
> the next step would to build higher powered repeaters that can be placed on
> top of tall buildings.

Nice sentiment, but technically counterproductive for mesh networks. Wide
coverage nodes create/suffer the “hidden transmitter problem”. Mesh
performance degrades overall. Smaller footprint repeaters, and more of them,
are a better solution.

~~~
vageli
> > the next step would to build higher powered repeaters that can be placed
> on top of tall buildings.

> Nice sentiment, but technically counterproductive for mesh networks. Wide
> coverage nodes create/suffer the “hidden transmitter problem”. Mesh
> performance degrades overall. Smaller footprint repeaters, and more of them,
> are a better solution.

Could you go into more detail on this/share any readings? As a ham radio
operator I have learned this through experience but wonder if there are any
papers on this idea.

~~~
dbcurtis
The ham packet radio literature has the most readable descriptions. The
professional RF networking write ups that I am aware of are pretty old because
I have not followed networking much since grad school (back in the last
millennium). Sorry about that.

Basically, you probably already know this, but for others reading along: The
RF networking channel differs from a wired net in that not all stations can
hear each other. So for stations of relatively equal performance, the stations
on the edges do not hear each other and must relay through a station in the
middle. It follows that those stations perceive channel busy/clear
differently.

With a high level station, first off it hears many more stations so can not
transmit into a clear channel as often. Then, when it does transmit, it has a
large footprint and prevents channel re-use by several lower-level stations
that would otherwise have different locally-clear channels.

------
xtat
There are so damn many far superior systems in this thread. We should have
gotten together earlier and promoted one of them.

------
JohnJamesRambo
I don’t know a lot about it but would Signal be safe or even possible to use
there?

~~~
stefek99
No internet, no Signal.

No internet being key here.

------
reustle
IIRC this was built on StartupBus, great to see it still being used

------
commandlinefan
Obviously since it’s the only safe option, I can see why the Chinese are using
it, but I have to wonder what sort of bandwidth can realistically be supported
by any mesh network.

~~~
jorgeribs
Basically anything text-based (messages, location, triggers), and as
technologies improve, so will Bridgefy as it's protocol -agnostic :)

------
leegr
Cool

------
imglorp
Don't they require a state-run app on everyone's phones as part of their
social credit system? It should at least know who is using the mesh app if
nothing else?

~~~
hkmurakami
I don't think that applies to HK (yet), which auxiliarily is related to what
the protesters are protesting about (separation of legal zones)

~~~
loyukfai
Right.

AFAIK, even in China you're not required to do such except perhaps being a
Uyghur in Xinjiang...

However, the PRC government is believed to have full access to popular apps
like WeChat, among other surveillance tools.

If I were to do it, maybe I'd just ask phone makers to install such tools as
system or ring-0 apps. Why would I give the people a chance to choose whether
to participate in my mass surveillance scheme?

