I crossed paths with someone who I believe is a bad person in a professional
setting and I’m afraid that they know that I know something. Do you know if
it’s possible for somebody to listen to my cell phone conversations remotely?
I’ve never used the phone for internet and nobody has physical [access] to the device
but me and I do not use Bluetooth. It’s a Boost mobile phone. I don’t expect
that you’ll have time to answer this especially because it’s not directly a
computer a question, but if you do, please don’t include any identifying
In this excerpt from
Answercast #60, I look at the problems and possibilities of eavesdropping in
on cellular phone calls.
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Cell phone snoops
Well, OK, no identifying information included other than the fact that you
have a Boost phone.
So the short answer is yes and no.
Here’s the problem. First of all, old analog phones (which I believe are
actually no longer supported by the network) – absolutely! They could be
listened to. They are simply radios and radios can be listened to with the
These days, all of our mobile phones are digital. Even when we’re not using
mobile data, the actual phone calls we make are converted to digital data.
Calls are encrypted
That digital data, as it turns out, is indeed encrypted. The intent is that
the data cannot be eavesdropped on as it’s transmitted over the air because
it is still fundamentally a radio and anybody with a radio tuned to the right
frequency could technically listen into the data.
That’s why encryption is important.
Now, here’s the bad news: the encryption standard for most of our digital
phones these days is so old that it is designed to work with very, very weak
hardware: what today we would consider to be very, very underpowered
What that means is that even though it’s encrypted, it’s actually not that
hard to decrypt. The algorithms aren’t that strong and the amount of processing
power that it takes to decrypt a telephone call these days isn’t really that
Equipment and range
Now, to go back to some good news here, it does take special equipment. So
someone would actually have to have a specific intent to go out and start
eavesdropping on cellular phones in order to be able to eavesdrop on your
phone. And yes, they would need to be within range; within radio range of your
So, consider what the range of a phone is. In line of sight, it’s what? A
mile, two miles? Whatever the distance is to your cellular towers that it’s
So the chances of somebody actually going through the effort (even though
it’s not computationally expensive)… the chances of someone getting the
specialized equipment to be able to do this, setting up the software to be able
to decrypt what it captures – that’s not really that common. It’s not something
that I worry about very much at all.
If you are of course the target of somebody who has the ability, who has
the resources, who has the desire, who has the whatever, to do this, then yes,
it’s certainly possible.
Cell phone privacy
I certainly wouldn’t consider a digital phone call to be private for
example from (I don’t know…) intelligence agencies worldwide. The encryption
just isn’t that strong. You’d probably want to layer some other kind of
encryption on top of it.
But the short answer is that while it’s possible that cellular telephone
calls can in fact be listened in on, it is difficult enough that it is just one
of those things where somebody would really have to go out of their
way for it to happen.
That’s unlike wireless networking or Wi-Fi – where anybody with a laptop
basically has everything they need to listen in to an open Wi-Fi conversation.
All they need is some software and the software is available for free.
When you go to things like cellular phones, digital cellular phones, you
need specialized hardware, you need specialized software that most people
don’t have – and to be honest, I wouldn’t even know where to start to go get
Next from Answercast #60 – How
do I properly secure a mobile broadband hotspot?