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chill's Journal: Lies of Omission 6

Journal by chill

This is a duplicate of a post I made in one of the recent topics. I'm copying it here for easier reference as I send it to a couple friends.

* * *

So what exactly is metadata?

Many years ago I was a telecommunications engineer for a large company and worked CALEA. For the uninitiated, that is law-enforcement wiretapping.

My job was to make sure CALEA functioned properly on the new cellular network. We tested on an internal, micro-cell network that was isolated from the real world. The end result was to make sure targeted devices sent CDR (call data records, or metadata) and voice to the destination. This was all piped thru IPSec tunnels to the appropriate destination law-enforcement agency.

In the event of a tunnel failure, CDRs were required to buffer but voice was not. Saving voice during an outage required too much storage space, but the text nature of CDRs meant they were small and largely compressible.

Metadata consisted of EVERYTHING THAT WAS NOT VOICE.

To be clear, it included the following:

called number
calling number
time of call
duration of call
keys pressed during call
cell tower registered to
other cell towers in range
gps coordinates
signal strength
imei (cell phone serial number)
and a few other bits of technical information.

Everything above "cell tower registered to" applies to traditional, POTS land line phones. This information seems to be what the disinformation campaign currently going on seems to revolve around. They never mention that there are over 327 MILLION cellular phones in the U.S., which is more than one per person. They never mention the bottom set of metadata.

Capturing all key presses makes sure things like call transfers, three-way calls and the like get captured.

It also grabs things like your voicemail PIN/password, which never seems to get explicitly mentioned.

But the cellular set is more interesting. This data come across in registration and keep-alive packets every few seconds. This is how the network knows you're still active and where to route calls to.

But by keeping all this metadata it allows whomever has it to plot of map of your phone's gross location and movements.

By "gross", I mean the location triangulated from cell tower strength and not GPS coordinates. Towers are triangular in nature and use panel antennas. They know which panel you connect thru and can triangulate your location down to a few meters just by the strength of your signal on a couple different towers.

GPS coordinates are "fine" location. For the most part the numbers sent across are either zeroed out or the last location your phone obtained a fix.

GPS isn't turned on all the time because it sucks batteries down. If you own a phone you know how long it can take to get a fix, so this feature isn't normally used.

HOWEVER, it can be turned on remotely and is a part of the E911 regulations pushed to help find incapacitated victims after 9/11.

[There is a reason the baseband radio chip in your phone has closed, binary-blob firmware -- whether or not the OS itself is FOSS. We wouldn't want the masses to be able to disable remote activation, would we? Or let them start changing frequencies and power levels.]

So, are we comfortable with the government knowing where we, thru our cell phones, are at every moment of the day? Because that is what metadata allows.

Think of what can be learned by applying modern pattern analysis to that data set.

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Lies of Omission

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  • If I see it in the firehose I'll certainly vote it up.

    • by chill (34294)

      Thanks, but I'm curious how it gets modded in the discussion and whether or not there are any comments here in the Journal.

      I've posted an abbreviated version over at HuffPo, and it has basically been ignored. Nothing new there. Only snark gets faved or commented, but still...

      I've watched here on Slashdot for almost a decade now and stories on gov't spying on telecoms gets very little traction. Your average Apple or XBox story gets more comments.

      The reality is, most people either don't care or think "they on

      • by RockDoctor (15477)
        What surprises, and depresses, me is that people didn't figure out the necessity for most of this within a couple of months of getting their first mobile phone. "How does it do that?" seems one of the basic questions to me.

        There do seem to be a lot of awfully stupid people out there.

        • by chill (34294)


          The trait of curiosity where people are compelled to figure out the whys and hows of things is rare. It is what makes good engineers and geeks.

          It is also the #1 trait I look for when hiring people. I don't really care about degrees, certifications or who you know. Show me you know how to think critically and figure things out on your own and you're top of my list.

          • The trait of curiosity is being trampled by the bullyism that is so highly rewarded in society. And that is why gangsterism is really the type of 'governance' we all live under. Just look at the types of people that money and power attract. They can smell it, and if you have any at all, strange and unwanted people start showing up at your door. The weak carny hucksters and two bit hustlers who won those colored pasties they wear on their chest (over the uniform, I don't know why. That's kinda like wearing y

  • by Eivind (15695)

    From todays discussion it seems likely that the NSA stores not only all of the above, but the actual call-content too. Just saying.

    Not that it detracts from any of what you say.

"Text processing has made it possible to right-justify any idea, even one which cannot be justified on any other grounds." -- J. Finnegan, USC.