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

Do you trust the 3G module? That is, if it claims it is off, do you believe it?

  • Yes (>99%)

    Votes: 56 43.4%
  • Probably (67%-99%)

    Votes: 40 31.0%
  • Don't know (33%-66%)

    Votes: 7 5.4%
  • Probably not (1%-32%)

    Votes: 13 10.1%
  • No (<1%)

    Votes: 13 10.1%

  • Total voters
    129

klapse

Central Scrutinizer
Joined
Aug 30, 2012
Messages
1,932
Location
Germany
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_

Advanced Member
Joined
May 5, 2013
Messages
1,170
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

Mega GP Mania
Joined
May 24, 2008
Messages
16,733
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_

Advanced Member
Joined
May 5, 2013
Messages
1,170
But isn't it analog in the sense that different currents above the threshold will result in different brightness levels of the led?
 

WizardStan

Mega GP Mania
Joined
May 24, 2008
Messages
16,733
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

The voice of reason, sense and exasperation
Staff member
Joined
Aug 15, 2006
Messages
2,707
Age
48
Location
South of Sweden
...unless it is very high current. Then you get very high brightness levels. And lots of heat. :D
 

levi

Still fresh, damnit!
Joined
Oct 6, 2008
Messages
12,598
Location
Somewhere off the coast of the EU
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.
 

_jr_

Advanced Member
Joined
May 5, 2013
Messages
1,170
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

Mega GP Mania
Joined
May 24, 2008
Messages
16,733
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.
 

Askarus

Hardcore Member
Joined
Sep 28, 2011
Messages
4,454
Location
Germany
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.
 

_jr_

Advanced Member
Joined
May 5, 2013
Messages
1,170
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

Hardcore Member
Joined
Sep 28, 2011
Messages
4,454
Location
Germany
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

Glowing ember
Joined
Apr 15, 2011
Messages
5,061
Website
portfolio.anotheragency.no
_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
 
Last edited by a moderator:

_wb_

Microbe
Staff member
Joined
Apr 5, 2012
Messages
5,387
Age
39
Location
Brussels, Belgium
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?
 
Last edited by a moderator:
Top