In comp.dsp Michael A. Terrell wrote: (snip)
And then there was the system that adds a sine wave to the video signal such that the sync is not the lowest level anymore, and wonders around enough that you won't try watch it.
-- glen
20 MHz analog bandwidth and 40 MB/s data rates have been available for about 10 years for telemetry receivers with excellent Doppler compensation.
-- Offworld checks no longer accepted!
Hopefully, the video of them ramming a drone up a terrorist's ass as he runs for his life will be leaked. It would be great for morale on both sides. :)
-- Offworld checks no longer accepted!
Everytime one thinks developers of systems know what they're doing, something like this comes out, and one realises that they didn't.
Sylvia.
They didn't do the video, just the audio. Video was a very simple inversion technique, that was trivial to break. The audio was DES (so they said) encrypted, but there were several holes in the system that rendered it a bit less secure.
krw wrote in news: snipped-for-privacy@4ax.com:
the US now has a very small Air-Ground Missile in development;it's called Spike(not the Israeli Spike ATGM),and is 2 ft long,5.3 lb total and has a 1 lb warhead,electro-optical guidance.It's intended to take out unarmored/lightly armored vehicles or single rooms in buildings and not cause a lot of collateral damage. A soldier can carry three missiles and launcher,and it can also be carried on the drones. it's like a small model rocket.
-- Jim Yanik jyanik at localnet dot com
glen herrmannsfeldt wrote in news:hgfngh$4cg$ snipped-for-privacy@naig.caltech.edu:
satellite TV like Direct TV/DishTV has always been digital; why do you think the picture pixellates or freezes when the signal is lost?
Jeez,that's ANCIENT.
-- Jim Yanik jyanik at localnet dot com
That's the sort of thing I recommend to stop "hot pursuit" situations...
Stop on an officer's order or we make you stop ;-) ...Jim Thompson
--
| James E.Thompson, CTO | mens |
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| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
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Help save the environment!
Please dispose of socialism properly!
And trivial to break. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Help save the environment!
Please dispose of socialism properly!
That was 'On TV' or the 'Hamlin' scrambling system on Cable TV. That was '70s technology.
-- Offworld checks no longer accepted!
Where did you find something that says that the video link to the Predator is the one that's being grabbed?
It is my understanding that it was the link to the ground station that was digital and being intercepted, not the link from the Predator. If you can point to some reliable source that says otherwise, let me know. I'll be mightily surprised.
DS
Jim Thompson wrote in news: snipped-for-privacy@4ax.com:
Heck,-I- want a launch rail on MY car.
-- Jim Yanik jyanik at localnet dot com
This is precisely a question I have asked myself with regard to a few of the other posts.
I work with digital communication 5 days a week, 3+ hours a day, including symmetric and assymetric cipher systems of the kind that might be used by the military, so some of the responses are just as perplexing to me as mine is to you.
-Le Chaud Lapin-
Anybody have plans for a rail gun ?:-) ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Help save the environment!
Please dispose of socialism properly!
To add more fuel to the fire:
IMO the lack of encryption was a failure in management. I would bet you a nickel that when the systems were being developed, the contractors said, "sure, we can add encryption, but it will add years and millions to the development schedule," and someone made the Executive Decision to skip it.
This is a major problem with many military and commercial contracts today: Often the people with the high-dollar decision-making authority don't have the technical background to know if someone pitching them a huge schedule and cost increase are doing so because what's being asked for really is a Hard Problem or just because the contractor doesn't happen to be very good in that area.
---Joel
Haven't found anything. All the articles on the subject are too vague. They are merely regurgitations of what the WSJ wrote, without any reliable specifics.
I took a quick look, and did not find any specifics, but once the information is digital, it is a done deal, as the only excuses remaining would be:
We know it is not #1, because a $100 PDA can easily do 128-bit symmetric cipher at reasonable rate for Wi-Fi link without killing the battery, which I tried several years ago.
We know that it is definitely not #2, because one video frame, at even low-res black-and white (not even grayscal) would swamp the 16-byte padding required for typical 128-bit symmetric block ciphers.
I think DARPA simply got lazy and punted on this one.
-Le Chaud Lapin-
That was Videocypher, I'm talking about DigiCypher, which was transmitted over "analog" satellite transponders...
Mark
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Or, it could be that
After all, management at these contractors are judged not by how well they hit the bulls-eye, but how much bacon they bring home. They last thing they want to hear is for one of their own people to say, "We don't really need $15 million to do this...a team of four of us could probably have a prototype in a month for $100,000."
One prime contractor that I spoke with during my utterly-depressing communications with DARPA & Company in 2008 boasted that "a single individual at DARPA" was solely responsible for giving his group $200 million over 8 years. It was sickening, because the "thing" they were making was simply pathetic. Not only that, we had a conference call one day, with three of their Ph.D's at the table, and I could swear that one of the things they were asking for was a compressor that could magically compress any data. I gently reminded them that there was no such thing, as well as the fact that it was was not even the topic on the agenda, and they kept coming back to it..."If you could find a way to compress our already-compressed data...we might be able to work with you." I tried to tell them that there was a limit beyond which it is theoretically and provably impossible, but they didn't want to hear that.
They have been using the same Microsoft Powerpoint slides to sell and resell the same piece of wood to DARPA and appropriations committees.
-Le Chaud Lapin-
The SkyGrabber site implies it works with DVB-S and DVB-S2 standards. I think it's dumb to use a standardized air interface on things you want to be very secure for warfighting, but that's just me.
Because satellite links are inherently power limited the modulations tend to be low, with QPSK being arguably the most common. 8-PSK is used sometimes, and DVB-S2 has some weird stuff in it IIRC, but nothing very high-order.
-- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com
I think he meant cracking it in real time. Certainly decryption in real-time isn't a big deal. Why any of it would be a problem in non-real time is anybody's guess.
-- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com
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