/tech/ - Technology★

Just do it over the radio waves. Exchange the encryption key ahead of time.

>>1016105 (OP)

How would having backup communications let you win a CTF? I don't get it, isn't a CTF just a game?

>>1016115

>Exchange the encryption key ahead of time.

Ah well that's exactly the issue I'm trying to resolve.

If my keys are compromised I need a way of redistributing them - and if I've lost my keys that's more problematic.

I'm worried about losing the keys to user error, phisical surveillance.

If I could send them all at once through an internal network to everyone even if our security was bad speed might still be able to cover us.

And since its a portable network, if the team has to relocate phisicaly (we lose power, someone runs on and cuts wires) we're in a much better position

>>1016122

In some games cheating is allowed.

There are applications that provide mesh networking communications. There are applications available for smartphones and desktop machines. There have been threads in the past about this technology but I forgot the names of these kinds of applications.

Here is a list of non-free applications.

https://www.geckoandfly.com/22562/chat-without-internet-connection-mesh-network/

>>1016143

That's the kind of thing I'm looking for, but these

A. Use Bluetooth or wifi, which are far too easily taped into - even encrypted

For one way communication they might be OK.

C. Use smartphones.

I'd rather use encrypted radio than these

I'm looking for something more sophisticated.

Hopefully by using mobiles as relays like in the tor network, someone listening wouldn't be able to work out who was the intended recipient and would only get a partial message if they had a D0 on one of the devices

>>1016176

Encrypted wifi isn't easily hacked. I don't know the state of Bluetooth encryption but I would speculate that they are secure.

>>1016178

>Encrypted wifi isn't easily hacked.

https://www.krackattacks.com/

Pleb, only cable is actually secure. Working encryption methods either aren't supported by the device or the router.

>>1016216

But they were too easily hacked if I remember correctly.

Could you make one secure?

>>1016223

This.

I thought it was common knowledge.

>>1016226

i'm currently on a Q10, since a while now, and the last, QNX based BBs were solid, but all depends if the BES admin is skilled; or a complete moron, for all the rest; VPN, secure client for mail, proxy, network authentication, these are the ThinkPad of phones.

No wonder RIM fell down and now is just a chink brand like the rest, but I know the only thing that could replace my Q10 could be only another Q10/Classic BB, or some Nokia flip phone.

>>1016141

Is it so common that your opponents disable your communications that you need a backup?

>>1016141

>If my keys are compromised I need a way of redistributing them

What is your use case for all of this?

There's no way to give you half-decent advice without knowing how your keys could be compromised and other things like that.

>>1016223

That attack has been mostly patched already, and the default windows implementation of WPA2 was slightly non-compliant and thus resistant to the attack.

>>1016291

The problem: routers don't run Windows

Lad, you don't even know how bad it really is.

Pick a secret passphrase and an evolution method, then use these with symmetric cryptography to transmit information safely.

For example,

Use passphrase ILoveGiantDicksInMyAss' and the evolution scheme of appending an incrementing number at the end, so your final secret is ILoveGiantDicksInMyAss69, and your next one would be ILoveGiantDicksInMyAss70.

Then, use a hashing algorithm to hash this so that your final key is e.g. SHA256(ILoveGiantDicksInMyAss69). This is so that even if your key is compromised all they have is a hash you can easily replace.

Now use this hash to encrypt whatever you want to communicate with each other. Share more private/public keys, whatever.

If your key gets compromised, simply leave a message encrypted with the compromised key out in the open that your buddy will be ableto find and then increment by one and re-hash and use the new totally unique key going forward. Unless the super ultra secret gets compromised (which it won't unless you're stupid and write it down somewhere) you will both understand how to generate psuedo-random but identical keys independently of eachother without having to communicate a word. If you can't decrypt something, just try a few different values for the incrementer until you find one that works.

>>1016302

There are a number of ways to make this more safe. Like not re-using the same incrementer for more than one message (thus if two appear with the same count you know something is fucked). You could also make the incrementer an unix timestamp and just make sure you and your buddies are time-synced relatively well and so you have a new nigh-unbreakable key literally every second.

>>1016105 (OP)

If you're not a ham the best bet is the Trisquare spread spectrum walkie talkies, the transmissions are encrypted and operate right across the unlicensed 2.4 GHz band. While it's certain that the NSA or other bodies could receive and decrypt your communications it seems unlikely that other groups would have the equipment or expertise to identify and intercept such transmissions. These radios were pulled from the market but are still available used.

Using pagers isn't that bad of an idea except for two things, first they operate in licensed bands which means you're going to get busted unless you reband them, and second, the communications protocol doesn't support encryption so you have to send out each message with IDs of the recipients. There's no way to send out a message to every pager in a given area.

Hams will use NVIS and other low probability of intercept techniques, including piggybacking on stronger transmissions, to get through without detection.

>>1016365

That sounds interesting. Are there perhaps any Chinese walkie-talkies with encryption available?

>>1016303

Throw in a Markov chained offset to the timestamp for autism.

>>1016389

Not that I know of and the Trisquare encryption like that used in all radios isn't exactly secure against the NSA, but it would stymie local cops and most any non-state group.

>>1016303

>>1016291

I'm worried we're going to lose our keys to members of the team we can't trust, or to someone with phisical access to our hardware.

It's not an easy task to secure a network that potencially could be compromised by an insider and I'm way out of my depth -hence backup communications are vital to ensure we have some base level connectivity which we can use to re-establish control

>>1016277

Just what I was looking for, thanks anon

>>1016289

It's almost a weekly occurrence *sigh*

We have office staff who are fooled by the most basic Phishing, people impersonating technicians to gain access to our hardware - usually to steal our files but sometimes to try and bug us.

We also suffer from repeated power outages and are occasionally forced to relocate the whole fucking operation because of among other things security threats, petty political infighting, natural disaster and infrastructure failure.

If I can set up a secure mesh network when - for instance - our whole neibourhood looses power and they can't fix it, I can use the backup because it's battery powered to coordinate the relocation.

>>1016302

Bingo, I think this is my solution - with >>1016277 I can get it all done sensibly

>>1016365

Radio traffic is a big no - no

Devices could be cloned, and because the military uses them extensively the set ups to break them are definitely out there

Shit when I was 15 we used to hack the local cops radios for funsies, so they got cheap encrypted ones but since we could see what kind they had we bought one off ebay, literally called the distributor pretending to be cops and complained our radio didn't work.

The cheese fingered motherfucker was angry because it was the sixth call that month or something and step by stepped us through how to do it, he knew everything because the cops told him and didn't even consider we might be a bunch of kids.

I'm not a tech expert, I don't know shit.

I just think outside the box and ask /tech/, God bless you all

HAM is as I understand it hard to phisicaly relocate and would probably fail if we had a power outage. That's almost a daily occurrence.

>>1016295

>routers don't run Windows

But many devices connected to routers do, and they were immune from the start thanks to them rejecting the new key.

You can still do denial of service that way, but you can't get to the data they are sending.

>>1016472

>I'm worried we're going to lose our keys to members of the team we can't trust, or to someone with phisical access to our hardware.

That's essentially the hardest scenario possible.

Ideally, limit attack surface by limiting what hardware contains important data: for example, personal devices only get a temporary key, while the master key is held only on the auth server in a secure location.

So to recap.

If I set up a mesh network of blackberries, set them all to a remote time zone (Bermuda), set a key (opisafaggot)and added an incrimentor (Bermuda time*3) that way everyone could check the incrimentor on any device in a blackout.

I would then have a key that evolved by the second which anyone with a key could follow.

That way someone getting access to the message would get a useless Hash code, someone with the Hash algorithm couldn't do much without the key, someone having the key, Hash would get a message - but unless they were aware the key evolved they wouldn't be able to follow past the one message they got

But would the mesh of blackberries be venurable to DDOS after it came online?

>>1016472

>It's almost a weekly occurrence *sigh*

I still don't get it. What's your line of work that all that shit happens to you?

>>1016472

>Radio traffic is a big no - no

Worked for Ham Nellie Ohr...

>HAM is as I understand it hard to phisicaly relocate and would probably fail if we had a power outage.

Most hams have their own power generation capability, it's part of the hobby. Every year we have Field Day where you practice operation on emergency power away from your own shack. I personally have over 180 amp hours of 12v lead acid batteries which I charge with a solar panel, it's enough for me to operate my radio station for hundreds of hours. And I'm a lightweight when it comes to this stuff.

>>1016653

It's a nice rig especially for the price but the batteries are going to be hard to obtain / old cells soon. Hopefully some based ham accessory maker produces some new ones.

>>1016635

Now that's an idea I hadn't considered

Wouldn't it be very obvious though?

Maybe your messages would be secure, but you couldn't possibly hide that kind of radio traffic.

A mesh network would have a much shorter range.

If our computers go down because of a general outage and we start beaming encrypted radio it would be like shooting flares into the sky.

I want to hide our messages in regular mobile traffic streams.

But it's a very good idea and I'll add it to the chalk board

When we were hacking radio we were talking over an antenna, communicating with it via internet so we could hide what we were doing (relaying a police signal would get noticed pretty quick).

We could decrypt it with a professional program, I couldn't even tell you what kind of encryption because I was a skiddy. All the work was done on computer, we acquired the radio encryption key and were stepped through how to tune in by the clueless police tech guy.

When it was set up we had lag, but got to hear all the private transmittion of the local criminals locations, and ongoing investigation. Nobody I knew you caught by the booze bus after that.

>>1016644

Disaster response capacity building.

It's a broad field, we have to make sure nobody forgets to have a water store at every center, that all the NGOs in the area speak the same language (we once had Korean missionaries, local response, French doctors all trying to work together and were forced to enlist tourists as internal translators).

Post disaster our teams are very venurable, one major concern is the army or militia might steal our supplies or kidnap our medical staff.

Lots of shit happens, so I'm trying to get coms set up.

We keep getting hacked, almost daily.

So I'm setting up a back up communications system so in a disaster we can move supplies and personelle out of the city, security is paramount but discretion is equally vital

>>1016644

People sometimes live in the hinterlands and if a tree falls on a line it might be a day or two before the power is restored. At my bolt hole in northern MN we lost power for six days a couple summers ago. No problem except for the fridge.

>>1016661

Numbers stations and one time pads etc are great if everyone has hours to decpyher shit and your recipient is a spy.

I'm broadcasting time sensetive evacuation messages to a bunch of doctors.

If their phones run on a mesh network they can use it like they would normally.

And I'm very reluctant to broadcast anything at all before it's absolutely nececary, I don't even want anyone to know what our back up channel is

Ideally I want an encrypted mesh network I can load onto some phones which I've partially disabled, I can put them all in a box and nobody be the wiser)

>>1016747

I'm sure, "doctors," just like all commie agitators are "students" or "professors."

>>1016745

>We keep getting hacked, almost daily.

Phishing? Windows viruses? Or something more complicated?

>>1016747

And also WHO is hacking you so much that you are afraid of even using your backup comms?

>>1016176

>Bluetooth, Wifi

Could go with Zigbee radio or maybe NFC...

>>1016223

Could just IPSec over a firewalled and gateway-less Wifi, or some other encrypted transport layer solution.

The only devices that will work after any EMP disaster will things w/o transistor tech. That pretty much reduces it down to tubes or even lower tech.

>>1017151

Most electronic devices will still work after EMP (unless the EMP is right on top of the device). An EMP is not a deus ex machina for crying out loud! The main thing that will be rendered FUBAR by an EMP is the electrical grid.

>>1016661

>nonsense 3/4 of the time so it prevents any kind of deciphering

you don't need nonsense for OTP

but even then, yeah I guess you could do frequency-hopping spread spectrum OTP, but not really necessary

OTP changes based on time anyway

>>1016277

BB was never secure

>>1017251

This, it was proved in court, too.

>>1016732

Just hook that bitch up to a deep cycle battery and you're in business.

>>1016732

It's a stupid nimh battery pack, how hard can it be to rebuild it?

bumping

Has anyone used any of the GoTenna products? They seem pretty ideal for small, portable devices with low barrier to entry for noob family members. Expensive, though. I'd rather an X200 with an APRS setup, but that's probably not maintainable remotely in a SHTF scenario.

https://www.gotenna.com/pages/mesh

>>1029649

> while they publish all the device locations on their network map.

From the very image:

> "We respect your privacy & do not track your goTenna Mesh device."

> " This map is not live, all nodes are self-reported"

Other than that, all good points. I guess it really only has value when there are thousands of users.

>>1029665

mesh memes wont really work anonymously. cant connect to others if you dont know where they are

>>1031181

>Pen and paper

"Nikolai Kovalev, the former director of Russia’s Federal Security Service, told Izvestiya: “From the point of view of security, any means of electronic communication is vulnerable. You can remove any information from a computer. There are means of defence, of course, but there’s no 100 per cent guarantee they will work. So from the point of view of preserving secrets the most primitive methods are preferable: a person’s hand and a pen, or a typewriter.”"

https://www.telegraph.co.uk/news/worldnews/europe/russia/10173645/Kremlin-returns-to-typewriters-to-avoid-computer-leaks.html

>>1031181

>10,000 cans

>1 can opener

lel

>>1031187

>or a typewriter.

non-electronic only

>>1031189

*non-electric

>>1016745

TV-WS