Any ideas how to start a secure communications network in case members of a team can't communicate on their own devices?
In an office I was thinking ye olde internal phone lines might work well. You could also send code visually through fax, the recipient scans the print out. Each colour of ink would give you a bit of entropy if you were sending a key.
What about using a set of identical paired mobile devices with reduced functionality that work like TOR? Your 10$ Nokia sends a encrypted message split to 5 other 10$ Nokias, it's then sent to the recipient.
Nobody would even know you had this kind of back up network until you started using it- and even then they might not be monitoring it have access to the Telecom network. You could use satellite phones if required.
Just do it over the radio waves. Exchange the encryption key ahead of time.
Parker Nguyen
How would having backup communications let you win a CTF? I don't get it, isn't a CTF just a game?
Ryan Myers
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
In some games cheating is allowed.
Joshua Kelly
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.
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
Luke Wood
Encrypted wifi isn't easily hacked. I don't know the state of Bluetooth encryption but I would speculate that they are secure.
