With all the NSA mass data collection on us going on, is there a way for we Americans to encrypt our phone calls and to randomly change our IMEI numbers with each phone call?
It's not illegal, I already know that, at least not in the USA
- NOTE: In Britain, I think it's illegal to change your IMEI but not in the USA. In France, I think it's illegal to use encryption, but not in the USA.
So, this is only a USA question:
Q: Is it possible for us to encrypt our (smartphone Android) phone calls (I have a Galaxy SIII with 4.1.2) and to randomly change our IMEI numbers?
NOTE: No individual can hide from a state-sponsored adversary should that adversary AIM for them; however, I'm not worried about them aiming specifically at me as much as my duty as an American citizen to protect what little privacy we have left (which is what this country stands for).
I should know better than to answer such a question.
I haven't tried it, nor do I plan to. The problem is that your cell phone account is tied to the IMEI/ESN number. You can change it, but in order to make a phone call, you'll need to inform your service provider. That pairs the new IMEI with your previous phone number, which is easily traceable. Unless you're dealing in stolen phones, juggling IMEI/ESN numbers on your own phone is a waste of time.
It may not be illegal (I don't know for sure), but it will certainly bring down the wrath of the cellular provider if you get caught. I almost had that problem. I've been buying and selling used cell phones for many years. In order to test the phones, I just change the IMEI/ESN number on the VZW web page or just do the *228 thing. After testing the phone, I would put the account back to my original phone. One day, I did about 15 phones in succession when I got an SMS message to call VZW. I was transferred to security, who wanted to know what the [expletive] I was doing. I played dumb and he eventually went away.
Not randomly. You need to make sure it's still the number for the same type of phone. You don't want to accidentally register a phone that doesn't have data or you may find yourself without data service. Also, with 7 billion phones and who knows how many devices out there, there's a fair chance you're going to either hit a phone in use or a stolen phone. You might want to check the IMEI/ESN first.
That's right. Errr... Far Right. So much for the science fiction. Now, let's do it the right way...
I don't think you're going to be able to do much inside the phone. You could probably write an Android SIP client with built in encryption and use the phone data only. That can get expensive but is probably secure.
A slightly more sane method is to use a handset with built in audio encryption. That scrambles just the audio, and will work over land-line, VoIP, Skype, as well as cellular. You can probably roll your own with a PIC that has an A/D and D/A inside. Well, maybe something smaller:
Voice codecs are (gasp) designed to work with voice. When you try to put anything other than voice through them, all bets are off. So playing with the analog audio doesn't work well over a codec.
Analog encryption methods don't work so well even on a POTS or NFM link. Schemes like frequency inversion for example. Some words shoot right through inversion since your ear/brain locks on the cadence. Rolling code inversion is a bit better, but really, you need to go digital for encryption.
I've been looking at what the feds buy for their secure SIP. You can trawl fbo.gov and look for yourself. Here is one example:
But it seems to me you are going to need to manage certs. It would be tough to call anyone at random and be encrypted.
If you have been to the NSA museum, they have an old analog encryption system that consisted of LPs and fancy turntables. Presumably each site had the same LP. I don't know how they phased locked the system, but it was a Bell Labs project, so they could have synced through the telco system on another line.
Basically if your "locals" are identical, you can mod/demod anything with a mixer. People have done this using broadcast signals as the modulation source, i.e. the audio from broadcast, not the RF itself. Of course you both have to be able to receive the same radio or TV station.
The Mumbai attack was coordinated with Blackberry BBM. Secure enough to confuse India. Incidentally BBM should be cross platform shortly. The apps for non-Blackberry devices have been submitted to the app stores.
Hey there Jeff, I know you're famous on a.i.w, so I respect your response.
I never understood WHY people say that the IMEI number matters to the telco. I put different SIM cards in my phone all the time, and thereby use either T-Mobile or AT&T and I haven't explicitly registered the cell phone with either company.
So, how exactly is an IMEI "tied" to the phone company? I never understood that.
The SIM card *is* tied to the company - but in my experience, it works in any (unlocked) phone of any IMEI.
So, that's why I never understood when people say you can't change your IMEI. You "effectively" change your IMEI every time you put your SIM card in another phone (which happens all the time).
Again, I don't understand any of these statements for the same reason as before - yet I highly respect your opinion. That's why I'm confused.
The only thing the telco cares about is the SIM card.
They don't care what phone you put it in. So, for example, if I borrowed your phone, and put my SIM card in it, then I'd have the same service as if I had that same SIM card in my cell phone.
The IMEI number was immaterial to the phone company (yes, I know it's transmitted to them - but it's meaningless to them from the standpoint of my service). [Yes, I know about the AT&T policy of smartphones having to have a data plan - that's a *policy* issue that only clouds the issue so let's ignore that unless it actually matters, bearing in mind that T-Mobile doesn't have that problem so it's not a technical issue.]
And, the argument that you have to have a "similar" IMEI number was used for MAC address changing also - but it's really statistically a weak argument. I doubt it would ever matter *what* IMEI number you used, since the chance of actually colliding with another duplicate IMEI is vanishingly small. Let's say I'd have a better chance of winning the lottery, so, IMEI collisions are a tiny issue that can easily be averted but since the chances are so slim, they're not even worth the effort.
And, while my argument has nothing to do with stolen phones, it's my understanding that in the USA, there is no stolen phone list. Certainly I've had *my* phone stolen (well, ok, I left it on a cafe table and it was gone when I returned) - and the telcos did absolutely NOTHING about it except replace my SIM card. So I don't think, in the USA, matching an IMEI of a stolen phone is also something to worry about.
The thing that confuses me is that the IMEI is nearly meaningless from the standpoint of the contract between the owner and his telco. I, for one, have a SIM card from T-Moblie, and they just shipped me that SIM card. That's it. I never gave them *any* IMEI, and I used that SIM card in multiple phones. They never cared.
The *only* effect, it seems to me, of randomizing the IMEI, is to keep the NSA off base, in that their meta data will be off by a tiny amount. Of course, if they were DIRECTLY observing me (which I hope they're not, then that slight inconsistency would be meaningless); but if they're on a fishing expedition, if EVERYONE changed their IMEI daily, it would benefit us all, by adding just one more level of privacy to our daily intrusions.
Just to reiterate, one of my cellular providers (T-Mobile) doesn't give one whit about the IMEI and doesn't make any statements in the contract regarding what phone I use.
The other (AT&T) does care, if only to gouge me for a data plan (which I never wanted and never needed).
But certainly it's not illegal (in the US) to change your IMEI number daily. So I watched that you-tube you referenced with interest.
Unfortunately, I'm on Android, so, I need to see if it can be transposed.
The GSM providers (AT&T and T-Mobile) use SIM cards for identifying the owner and the account, but not the phone. The CDMA providers (Sprint and Verizon) do not use SIM cards. Instead, they use the MEID/IMSI/IMEI/ESN numbers. When you activate a phone on Verizon, it's by those numbers: On a smart phone, dial *#06# to display the number(s). What the IMEI number does for the vendor is identify the phone and it's capabilities.
The external audio scrambler was obviously for voice only. I forgot to mention that it doesn't work well with data, fax, or analog modems.
Really? Remind me to intoduce you to the local commerical fishermen, all of whom use voice scramblers of one form or other. It works just fine over VHF marine radio. Not so well over the new narrow band FM radios. Most popular technology seems to be rolling code inversion. For example:
They do go digital. Inversion is too easy to decode. Any computer that can simulate a multipler, tone oscillator, and low pass filter, can demodulate speech inversion. If you look at the spectra on an analyzer, you'll see a "hole" or dip at the inversion frequency. The inversion frequency will hop around, but I'm told a DSP can mostly follow it. Extra credit for speech inverters with carrier leakage at the inversion frequency.
The latest for long range is a GPSDO (GPS diciplined oscillator). As long as the pseudo random codes are time synced, everything sounds quite clear.
RIM/Blackberry is losing customers to Apple and Android devices and is finally opening up their network to competative devices.
I can tell you for UMA, they need the IMEI. I bought an unlocked phone and could not UMA until T-mob had the IMEI.
The phone call itself uses the IMSI, TMSI, and sometimes P-TMSI. I'm not sure it used the IMEI. The system works hard not to put on the IMEI. That is what the TMEI is for.
Depending on my much you know about your phone, you can get these numbers. My TMSI and P-TMSI are 8 hex digits.
Looking at my IMSI, the first 6 digits are obvious:
I can read out just about any number my phone uses. I can also read the simcard. However, putting this stuff out on the internet..well...
The Serbs used these speaker-mics during the war. Really terrible. Easily defeated by any intelligence agency. If Somalia had a NSA, they could defeat the system.
Like I said, rolling code works. But that is NOT a simple inversion scheme. Rather, the change the code in a psuedo random manner. MXComm used to make those chips. [I'd have to see if they are still in business.]
In the 80s, I was doing modem chips. We had plenty of voice band mixers handy and tried simple frequency inversion. Some words shoot right through. Cadillac for instance. You could even tell the difference between go and no. The CADOJ used to use these frequency inverters, but there are computer programs to decode them with sound cards. There are
555 plus op amp circuits to do simple inversion decoding.
The GPSDO is just an accurate time base. I have a Starloc. You are probably thinking of something else.
Hi Jeff, Ah. I knew you knew what you were talking about, since I know you. So I'm glad you clarified. I never think about Verizon, since I'm a GSM person nowadays. So what you're saying is that, for CDMA telcos, they *need* the IMEI to verify the account.
But, for GSM telco's, the IMEI is a (nearly) meaningless number from the standpoint (only) of identifying the account.
The IMEI, as you noted, is certainly a predictor of the telephone capabilities though - but that's not the reason for my concerns so I won't worry about data plans and software upgrades.
My Android phone isn't rooted (and I'm not really sure what that even means) so, my first order of business is to figure out how to ROOT the Android phone. Then I can worry about installing the terminal emulator. And then I can change the IMEI.
On T-Mobile GSM, do you predict any negative repercussions from daily changing the IMEI number (assuming I generate a valid IMEI number)?
Is this summary correct? UMA stands for 'unlicensed mobile access', which, as far as I can tell, simply means the phone can switch from WiFi (or Bluetooth) to GSM (or CDMA) and back, while making phone calls.
Since I have T-Mobile, the IMEI might matter because T-Mobile has to, somehow, "enable" my phone to switch between WiFi/Bluetooth and GSM.
But, that's a second-order issue. I'll first see if I can change my IMEI number by the suggested method.
Once I change it, I can tell if there are any unexpected side effects.
I wouldn't doubt that the NSA has *every* nntp poster identified; and, if they cared, they can correlate each of our posts to our cellphones (and other identifying metadata) at the click of a button.
Luckily, the keyword for 99.99% of us is "if they cared", as if they did, we'd be dead as OBL.
Thanks. Since I'm GSM, I wholly missed the part about CDMA needing the IMEI number. Reading his story of how he got in trouble with them, I couldn't fathom how T-Mobile would have a similar problem.
Now I realize that, for CDMA, the IMEI might matter a lot.
Luckily, I'm on GSM; so the IMEI is (apparently) nearly meaningless from the standpoint of the carrier figuring out whether or not to supply service to me.
They get all that from the SIM card information, not from the IMEI. Which leaves me to change the IMEI at will.
Of course, now that I realize all this, changing the IMEI might not give me the obscurity from the NSA that I desire, simply because the SIM card will just as easily uniquely identify me.
Sigh. (as I slam my tinfoil hat down on the ground)
I used the Daisy back in the day. What was it we did? Sing, drink, dance? I've also run the old Calma GDS1 with the storage screen, but never the digitizer. Also the old Aplicon that used the gestures way before people talked about gestures.
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