[poll: vote now!1!!] 3G paranoia: Discussing solutions

[Binky]

Poe's law applies strongly to the last few pages here

 

[klapse]

I think the hardware-LED modem activity light is a good idea

It's not an activity LED, it's an on/off LED only. And would it really be that much more of a benefit for it to be hardwired vs software controlled?

I see. I think most useful would be a hardware controlled activity LED for wifi and 3G. Second place would go to a software controlled activity led. A hardware controlled power LED would still be useful.

 

[_jr_]

If it is directly connected to the power line and the power spikes during communications as described by GTA it seems like an activity indicator to me, but I could be totally wrong on this.

 

[WizardStan]

gta04 is talking about using a series resistor as a very simple switch, tuned to a specific current: when it exceeds the current threshold, the LED turns on; when it drops below the threshold, it turns off. I guess you could probably tweak it so that it only comes on when the power spikes happen but then it could be on (and therefore connected to a tower and being tracked) and you wouldn't know, thus negating the benefit of a hardware identifier.

 

[_jr_]

But isn't it analog in the sense that different currents above the threshold will result in different brightness levels of the led?

 

[WizardStan]

Electricity doesn't work that way, unfortunately. Different voltages would produce different brightness levels, but you can't just put current into a circuit like that.

I'm not sure how to explain it, just suffice to say that no, higher current would not produce different brightness levels.

 

[moxie]

...unless it is very high current. Then you get very high brightness levels. And lots of heat.

 

[levi]

As an aside, I've often wished the Pandora's network light would blink or something when it was actually connected to wifi, so I could tell at a glance whether it was hooked up or still searching (or had dropped off).


That's nothing that this power-based indicator would support as far as I can tell, just a thought that occurred to me as I was reading this thread.

 

[comradekingu]

https://rawgithub.com/mempo/mempo-websites/master/mempo-main/html/index.html

MEMPO debian project

 

[_jr_]

Electricity doesn't work that way, unfortunately. Different voltages would produce different brightness levels, but you can't just put current into a circuit like that.


I'm not sure how to explain it, just suffice to say that no, higher current would not produce different brightness levels.

Ah, ok. Thanks for the explanation. I assumed the voltage drop differences at the resistor would be big enough to be noticable.

 

[WizardStan]

It probably would if they put the LED itself in the series, but since gta04 said he was concerned about the voltage drop across a switch causing problems I doubt it could withstand the voltage drop from an LED.

 

[Klumpen]

 

[levi]

Um, okay.

 

[Askarus]

As said already:

What is an LED useful for if your Pyra will be hacked and you don't see your LED?

Nothing.

And I'm sure you don't watch that LED all the time.

It's just annoying when you see it. blinking.

 

[comradekingu]

http://neo900.org/news-0009-progress-update-march Suggested reading

TL;DR good guys are being awesome, and helping out. Rest assured thats as good as it gets.

 

[_jr_]

As said already:


What is an LED useful for if your Pyra will be hacked and you don't see your LED?


Nothing.


And I'm sure you don't watch that LED all the time.


It's just annoying when you see it. blinking.

I can watch the LED when it is important to me. That is an additional feature. Whether it is worth the cost is naturally subjective. To me it is.

 

[Askarus]

As said already:


What is an LED useful for if your Pyra will be hacked and you don't see your LED?


Nothing.


And I'm sure you don't watch that LED all the time.


It's just annoying when you see it. blinking.

I can watch the LED when it is important to me. That is an additional feature. Whether it is worth the cost is naturally subjective. To me it is.

And I have to watch it even if I'm annoyed of it.

That LED helps nothing.

Let's assume you enabled your 3G modem and brows the web, then there's traffic.

If someone sends you a virus then the LED doesn't show it to you.

It simply shows that there's traffic, not more. If someone sends some KB of data while you do webbrowsing is nothing you would notice.

The LED is meant to show you unwanted traffic from hacker attacks.

Hackers can attack you any time, not simply when you watch that LED.

There's only one use scenario for that LED to me:

You have a OS and sensible data on your Micro SD. You only boot from it when you want to deal with that sensible data. Then you can get surer that there's no Internet traffic when watching the LED.

The rest of the time you boot from emmc with no sensible data on it and hackers won't get anything.

 

[comradekingu]

_jr_ :

Is it also worth it to you to not be able to turn it off? Having a hardwired LED means exactly that.

Askarus stance is that a LED, if not hardwired, in a software configurable option, would limit access to it to the base system. Over which the modem doesnt have control.

In a sort of next level hack way you could determine then if someone pwned your system at which point it would be

1. too late to do something about it. You could rip the battery out before its initialized and transmitting (maybe), but no.

2. An attacker with system access could transmit whatever data it wants when you have enabled the modem yourself

This means you have to have to additionally analyze traffic and/or have various other measures, which is the case anyway, so the hardwired LED has no exta benefit when on, and is annoying when you want it to be off.

I think hardwired LEDs are false security and if you want to take hardware measures, make a switch.

Edit: tango down, sniped by askarus

 

[Askarus]

I prefer something like that:

https://rawgithub.com/mempo/mempo-websites/master/mempo-main/html/index.html

MEMPO debian project

Some good security software built in sounds a lot better to me than an LED.

Switch or Software, but LED is (mostly) useless (see comredekingu 1 and 2) and annoying to me.

 

[_wb_]

There are many potential security issues at various levels. None of them are solved with a LED, hardwired or not.

The only use I can imagine for a hardwired LED, is in case the software has bugs and does not toggle power correctly or misreports the status. But then I prefer that those bugs get fixed instead of having a LED -- what would I be supposed to do anyway if it does not turn on or off when it should? Reboot until it works or something?