Satellite Warfare Submitted Friday, October 22, 2004 - 2:42:10 AM by Klaitu
Alright, for my TV I have a Directv satellite system. I was cruising through the waves today, nothing interesting was on, so I decided to reset my channel list. Directv gives me something like 800 channels, the majority of which I have no interest in, or are not on my payment plan. For that reason, I set the receiver to just not list any uninteresting channels.
But DTV updates their service from time to time and adds channels to the mix, so every once and a blue moon, I set all the channels to show up, and then go about eliminating all the sucky ones again, just to make sure I'm not missing any goodies.
As I was doing this, I noticed that a great many of the channel logos that display when you flip channels were missing, or outdated. I began to wonder if there was a way to download new logos, or if those were just hard-coded into the system when it was bought.. so I did some checking. I didn't find the answer to thius question, but I dragged up a pretty interesting story, which I will now share here, because I want to, so nyaah! (again)
DTV has been around since like 1994 or so. We got it in 97ish if memory serves, and the first receiver we had was a primitive piece of equipment. After about a year of service, it burned itself out and we had to buy a new one. When we went to the dealer to get a new one, he was excited, and he said he would give us a discount if we brought in the old junky one. Free money? okay, sure, have our old piece of burned out junk.
Turns out that all he wanted was the DSS access card contained in the receiver. I guess it's too bad we removed it before giving it to him, and he didn't bother to check. See, the access card contains a magical chip which basically tells who can legitimately view DTV, and who can't. The old card we had was one that was particularly easy to hack.. this is essentially the age old game of "hey, you want free cable?"
Then, some time later.. about a year ago.. DTV sent us a whole new access card to put into our receiver. It came with easy instructions and took about a minute to update. If you have DTV, you probably got the same letter. They sent those out because they discontinued that certain kind of access card.. again, because hackers were going crazy with it.
All of this dosen't compare to the bit of coolness that apparently happened early this year, about a week before the last superbowl. You see, all those hacker guys had been using cards that they modified to get all the channels all the time. DTV didn't like this, so DTV would also constantly modify the cards through the satellite. So, then, the hackers would have to go and re-modify their card to adapt to the new changes.. if they didn't, their hacked card would cease to function.
Well, some smart guy.. or guys.. up at DTV stopped them in their tracks. You see, all these little downloads that DTV had been sending appeared to be just random bits of information intended to annoy them into submission. In actuality, DTV was assembling self-destruct program inside the card, and when the last piece fell into place.. BLAMMO, no more card.
Okay, so it didn't really explode, but it did render any hacked card useless, and impossible to update. Essentially it turned their cards into a little plastic paperweight, while leaving the normal cards functioning perfectly.
The way they did it was genius.. see, all DTV access cards come from DTV themselves.. when they're manufactured, they're all intended to be put to legitimate use, so they each have the same parts. When DTV sends down an update, it sends down an update to EVERY card that is attached to a satellite dish. DTV knows how the cards come when manufactured.. and knows what modifications that they themselves have made, therefore any other modifications made are not legitimate. Here's how it works (and I'm paraphrasing and translating into non-nerd speak)
The access card can't communicate with DTV at all, but it always listens to DTV, nothing can stop that. What DTV has done, essentially, is to explain to the card how to tell if it's legitimate, and to kill itself if it isn't. If it were a conversation:
DTV: We know you can hear us, but you can't talk back, so listen carefully. Remember the number 105, store it in your write-once memory. Card: (okay) DTV: Every time you start up, take that number we just gave you, and compare it to the number we gave you when you were manufactured. If those two numbers match, behave normally. If the two numbers do not match, check them over and over again until they do. Card: (okay)
So, now a card will do either 1 of 2 things. It will either see that the numbers match, and then proceed to do what it does normally, or it will see that the numbers do not match, in which case the only thing the card can do when given electricity is to check to see if the numbers match as fast as it possibly can, over and over infinitely.
Hacker's can't change the secret number that DTV gave it, because it's in write-once memory. In essence, it's a tiny microscopic fuse that has been blown.. the sort of thing you can't fix unless you have an electron microscope and teeny tiny tools.
Anyways, I thought that was a kind of neat story. Of course, Hackers are at it today, but it's a lot more work. Nowadays they've come up with a way to hook a PC into the slot where the access card goes, and then the computer pretends like it's a card. That way, that pesky write-once memory is actually "write as much as you want" and the hacker can go fix anything. Of course, if you're going to go to all that trouble, you might as well just freggin buy your own dish. It's a lot easier.
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