Driver to drive?

[Steve Pope]

Eric Jacobsen <eric.jacobsen@ieee.org> wrote:

On 12/18/2009 1:55 AM, Steve Pope wrote:

Le Chaud Lapin<jaibuduvin@gmail.com> wrote:

It should be noted that decrypting in non-real time, right now, in
December, 2009, is impossible using 256-bit AES.

WTF are you talking about?

I think he meant cracking it in real time. Certainly decryption in
real-time isn't a big deal.

Thanks, that makes sense. I (as usual) was reading the sentence
too literally.

Steve

 

[Rick Jones]

In comp.protocols.tcp-ip Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

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:

1. Not enough power for cipher operations.
2. Overhead of padding consumes too much bandwidth for data link.

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 don't seek to excuse the US. DoD and/or their contractors but...

It is my understanding that as wizzy as "things military" are, they
tend to be built from components that rather lag in performance
compared to what is available to civilians. That is, "mil spec"
processors and what not are not at the forefront of the performance
curve.

http://en.wikipedia.org/wiki/Predator_drone

suggests the first ones at least entered service in 1995, which means
they were probably prototypes a couple years earlier, which suggests
they were designed with stuff from the late '80s.

Could a late 1980's PDA do 128-bit symmetric cipher at a reasonable
rate?

Now, there is still the question of "Well, why not upgrade the
things?!? This is the 21st century!" Indeed a very good question,
probably one that is deeply ensconced in what one might consider
analogs to layers 8 and 9 of the 9 layer model:

https://www.isc.org/files/9layer.thumb.png

(which should slightly bring it back OT for comp.protocols.tcp-ip

The main point though is that by and large, at least to my
understanding, military technology tends to lag, which means making
comparisons to contemporary civilian tech somewhat complicated.

rick jones
--
denial, anger, bargaining, depression, acceptance, rebirth...
where do you want to be today?
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

 

[JosephKK]

On Wed, 16 Dec 2009 00:57:15 +0000, Eeyore <rabbitsfriendsandrelations@removethishotmail.com> wrote:

Bill Sloman wrote:
On Dec 11, 3:04 am, John Larkin wrote:

Science used to rely on experiment.

Newton's astronomical experiments are famous, as are Darwin's
evolutionary experiments.

Physics in particular also relies on repeatable OBSERVATIONS.

Name a single observation that the warmingists can show is even real,
never mind repeatable.

Graham

Kind of difficult when Hanson et al., keep adjusting the data from what
the satellite reported to what they want it to have reported.

 

[John Larkin]

On Fri, 18 Dec 2009 12:50:29 -0800,
"JosephKK"<quiettechblue@yahoo.com> wrote:

On Fri, 11 Dec 2009 07:01:42 -0800, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
SNIP

I think I'll play with some latching relays today. I need to store
enough energy in enough capacitors to have an FPGA set the states of
75 relays *after* a power failure. About 12 volts, 1.5 amps for around
6 milliseconds should do it.

John


With that many latching relays no reasonable capacitor will hold up if
you try to switch them all at the same time. I found out the hard way.
I had to sequence them.

Why does sequencing help? Charge is charge. Only too much ESR would
suggest sequencing.

John

 

[Eric Jacobsen]

On 12/18/2009 2:00 PM, Le Chaud Lapin wrote:

On Dec 18, 12:35 pm, Eric Jacobsen<eric.jacob...@ieee.org> wrote:
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.

Some argue that security by obscurity not good, which I tend to agree
with:

http://en.wikipedia.org/wiki/Security_through_obscurity

I guess you know that the military has committed to moving toward IP-
based, commoditized components, to their credit, IMO. One of the
things they kept telling me was, "Whatever you give us, it has to run
over IPv4."

They have some outstanding solicitations with promising-yet-misleading
names like "Military Network Protocol:

http://www.darpa.mil/STO/Solicitations/sn09-04/index.html

...which gives the impression that it is a new protocol for the
military, but that is not what MNP is. Speculatively speaking,
soldiers in the field have been tying up precious downlinks by
downloading "unscrupulous" material, frustrating higher-ranking
officers who are trying to get real work done, or, perhaps, download
their own unscruplous material . The purpose of MNP is to allow
prioritized access to the inbound/outbound trunk based upon parameters
that at least includes the rank of the officer trying to use the link.
So if a rear admirer...pardon me....admiral, is hoping to download the
lastest from http://www.fhm.com/, he would simply start download, and
all captains and lieutenants would get booted off the trunk until he
is done.

There was another soliiciation which basically said, "Look..IPv4 is
great, and we are thoroughly convinced that packet switching is
superior to circuit switching, commoditization is good, yada...but now
we would like to take all the concepts of computer networking that we
have learned over the past 30 years and formalize them into a new
networking protocol that is both useful for public and military. Give
us Version II of The Internet, and make sure every ingredient is in
the soup pot, including security and mobility, maybe some multicast.
We do require that it be compatible with IPv4/6, so long as you give
us something revolutionary."

The program manager who was in charge of this soliciation mysteriously
disengaged not long after it was published.

-Le Chaud Lapin-

I was addressing the link, not the cryptography. Most security people
I've worked with recognize that layering barries is usually a good
thing, so why use a standardized link that anybody can buy a receiver
for when it's not hard at all to obscure the link protocol? That'd
make the barrier to just getting the signal MUCH higher, and require
some pretty specialized research to figure out. That's a step that'd
need to be done before one could even begin to address the decryption,
which is a different issue entirely.

But that's just me, what do I know?

--
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

 

[Eric Jacobsen]

On 12/18/2009 12:17 PM, Le Chaud Lapin wrote:

On Dec 18, 5:18 am, Sylvia Else<syl...@not.at.this.address> wrote:
Everytime one thinks developers of systems know what they're doing,
something like this comes out, and one realises that they didn't.

I have spent an some time pondering the process that yields this
result, and each time I arrive at the conclusion: It is all driven by
self-preservation and/or ego.

Or, perhaps more likely, budget and schedule realities. When you have
to meet a budget and a schedule, and the primary task (i.e., getting the
UAV flying properly) is consuming most of the resources (as it should)
then the links become a "get it working" task. I doubt in the 90s any
manager would think it wise to use up a big fraction of a budget to make
a UAV work on getting the link more secure.

Been there many times, it's not unusual. The fact that it's been that
way for so long is disturbing, but also not all that unusual in the
military/government management and procurement system. It usually comes
down to budget and bureaucracy limitations and priority setting. There
may have been other things in the program that were deemed (perhaps very
properly so) to have needed the attention more.

It's easy to be an armchair quarterback.

--
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

 

[Spehro Pefhany]

On Fri, 18 Dec 2009 12:50:29 -0800,
"JosephKK"<quiettechblue@yahoo.com> wrote:

On Fri, 11 Dec 2009 07:01:42 -0800, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
SNIP

I think I'll play with some latching relays today. I need to store
enough energy in enough capacitors to have an FPGA set the states of
75 relays *after* a power failure. About 12 volts, 1.5 amps for around
6 milliseconds should do it.

John


With that many latching relays no reasonable capacitor will hold up if
you try to switch them all at the same time.

Why would it matter? A reasonable 1500uF electrolytic charged to 24V
can easily supply 800mA for 6ms. If external resistance and ESR isn't
too high, then it's just energy storage that matters.

1.5A * 12V * 0.006 = 0.11J

Eg. EEV-FK1V152M (SMT, at that)

Ignoring losses, it will discharge from 24V to about 20.8V to supply
that energy. If a buck regulator works down to 15V then there is a
margin of more than 2:1 (to account for losses in the regulator,
capacitor tolerance/aging and temperature changes)

I found out the hard way.
I had to sequence them. Then again i only had room for 4000 uF per 10
relays. My reset drive was only 0.5 A for 75 ms per relay for
reliable switching. So i drove the reset totally sequentially. I could
pull the power plug and punch reset in that order and reliably get reset.
80 relays at 75 ms per comes out to some 600 ms. Not an unreasonable power
supply hold up for 25 to 30 years ago.

 

[Jerry Avins]

Le Chaud Lapin wrote:

On Dec 18, 12:35 pm, Eric Jacobsen <eric.jacob...@ieee.org> wrote:
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.

Some argue that security by obscurity not good, which I tend to agree
with:

http://en.wikipedia.org/wiki/Security_through_obscurity

I guess you know that the military has committed to moving toward IP-
based, commoditized components, to their credit, IMO. One of the
things they kept telling me was, "Whatever you give us, it has to run
over IPv4."

They have some outstanding solicitations with promising-yet-misleading
names like "Military Network Protocol:

http://www.darpa.mil/STO/Solicitations/sn09-04/index.html

...which gives the impression that it is a new protocol for the
military, but that is not what MNP is. Speculatively speaking,
soldiers in the field have been tying up precious downlinks by
downloading "unscrupulous" material, frustrating higher-ranking
officers who are trying to get real work done, or, perhaps, download
their own unscruplous material . The purpose of MNP is to allow
prioritized access to the inbound/outbound trunk based upon parameters
that at least includes the rank of the officer trying to use the link.
So if a rear admirer...pardon me....admiral, is hoping to download the
lastest from http://www.fhm.com/, he would simply start download, and
all captains and lieutenants would get booted off the trunk until he
is done.

There was another soliiciation which basically said, "Look..IPv4 is
great, and we are thoroughly convinced that packet switching is
superior to circuit switching, commoditization is good, yada...but now
we would like to take all the concepts of computer networking that we
have learned over the past 30 years and formalize them into a new
networking protocol that is both useful for public and military. Give
us Version II of The Internet, and make sure every ingredient is in
the soup pot, including security and mobility, maybe some multicast.
We do require that it be compatible with IPv4/6, so long as you give
us something revolutionary."

The program manager who was in charge of this soliciation mysteriously
disengaged not long after it was published.

The need to guard against cyberattacks on power stations and military
installations is a clear indication of bad -- make that stupid --
design. Critical facilities shouldn't share wire networks with
internet-at-large, and there would ideally be no radio links. Those who
don't like other people reading over their shoulders shouldn't build
glass houses.

Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ

 

[Le Chaud Lapin]

On Dec 18, 12:35 pm, Eric Jacobsen <eric.jacob...@ieee.org> wrote:

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.

Some argue that security by obscurity not good, which I tend to agree
with:

http://en.wikipedia.org/wiki/Security_through_obscurity

I guess you know that the military has committed to moving toward IP-
based, commoditized components, to their credit, IMO. One of the
things they kept telling me was, "Whatever you give us, it has to run
over IPv4."

They have some outstanding solicitations with promising-yet-misleading
names like "Military Network Protocol:

http://www.darpa.mil/STO/Solicitations/sn09-04/index.html

....which gives the impression that it is a new protocol for the
military, but that is not what MNP is. Speculatively speaking,
soldiers in the field have been tying up precious downlinks by
downloading "unscrupulous" material, frustrating higher-ranking
officers who are trying to get real work done, or, perhaps, download
their own unscruplous material . The purpose of MNP is to allow
prioritized access to the inbound/outbound trunk based upon parameters
that at least includes the rank of the officer trying to use the link.
So if a rear admirer...pardon me....admiral, is hoping to download the
lastest from http://www.fhm.com/, he would simply start download, and
all captains and lieutenants would get booted off the trunk until he
is done.

There was another soliiciation which basically said, "Look..IPv4 is
great, and we are thoroughly convinced that packet switching is
superior to circuit switching, commoditization is good, yada...but now
we would like to take all the concepts of computer networking that we
have learned over the past 30 years and formalize them into a new
networking protocol that is both useful for public and military. Give
us Version II of The Internet, and make sure every ingredient is in
the soup pot, including security and mobility, maybe some multicast.
We do require that it be compatible with IPv4/6, so long as you give
us something revolutionary."

The program manager who was in charge of this soliciation mysteriously
disengaged not long after it was published.

-Le Chaud Lapin-

 

[biject]

On Dec 18, 9:46 am, David Schwartz <dav...@webmaster.com> wrote:

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

The sad thing is at one time the government had good
laboratories like China Lake that could for pennies on
the dollar fix this problem in less than a month. But
the dumb people running the show in DC would rather keep
spending millions of dollars getting nothing done than
actually fix the problem. Contractors also seem to get
more money by promising to fix things and then even more
money when they fail. This country is in big trouble if
it still has minor problems like this. Bring back the
good labs where the only requirement is to get the job
done. Forget all the EEO rules and crap just hire competent
people who can get the work done. I know the team I
worked with could fix this problem if they had a chance
and no pain in the ass bureaucrats slowing us down.

David A. Scott
--
My Crypto code
http://bijective.dogma.net/crypto/scott19u.zip
http://www.jim.com/jamesd/Kong/scott19u.zip old version
My Compression code http://bijective.dogma.net/
**TO EMAIL ME drop the roman "five" **
Disclaimer:I am in no way responsible for any of the statements
made in the above text. For all I know I might be drugged.
As a famous person once said "any cryptograhic
system is only as strong as its weakest link"

 

[Le Chaud Lapin]

On Dec 18, 3:00 pm, Le Chaud Lapin <jaibudu...@gmail.com> wrote:

There was another soliiciation which basically said, "Look..IPv4 is
great, and we are thoroughly convinced that packet switching is
superior to circuit switching, commoditization is good, yada...but now
we would like to take all the concepts of computer networking that we
have learned over the past 30 years and formalize them into a new
networking protocol that is both useful for public and military. Give
us Version II of The Internet, and make sure every ingredient is in
the soup pot, including security and mobility, maybe some multicast.
We do require that it be compatible with IPv4/6, so long as you give
us something revolutionary."

* do not

The program manager who was in charge of this soliciation mysteriously
disengaged not long after it was published.

-Le Chaud Lapin-

 

[JosephKK]

On Fri, 11 Dec 2009 09:08:31 +0000, Martin Brown <|||newspam|||@nezumi.demon.co.uk> wrote:

Sylvia Else wrote:
Rich Grise wrote:
Found on rec.crafts.metalworking, not crossposted because we all know
what
happens when I do that!
----
On Thu, 10 Dec 2009 09:13:15 -0600, S. Caro wrote:
Cliff wrote:

http://www.google.com/hostednews/ap/article/ALeqM5j9MrjlmXzORMlHNvYfE9yAlgtiBwD9CGDL281

[
1,700 UK scientists back climate science (AP) - 3 hours ago

LONDON - Over 1,700 scientists in Britain have signed a statement
defending the evidence for human-made climate change in the wake of
hacked e-mails that emboldened climate skeptics. ....

Yea, but MY scientists are better than YOUR scientists.

--Over 31,000 U.S. scientists deny man-made global warming--

http://www.enterstageright.com/archive/articles/0508/0508gwpetition.htm


Is this a matter that's decided by a majority vote?

Unfortunately in the public mind there is still controversy about
whether or not AGW is happening. The science is now pretty well settled.
We are changing the atmosphere by measurable amounts and in the long
term it will have consequences - mostly for low lying populous areas
like London, Tokyo, New York, and New Orleans (not worth rebuilding).
And in some cases whole countries like Bangladesh on a river delta.

But it is exactly the same sort of manufactured controversy as that
about the risks of smoking or not wearing a seat belt when driving.
Indeed some of the same practitioners have been working as Exxon
sponsored denialists that were involved in keeping the suckers smoking
tobacco. Their product is spreading uncertainty in the public mind to
prevent people making a rational informed decision. It was so bad at one
point that the UK's premier scientific society wrote an open letter to
Exxon complaining about them deliberately misrepresenting the science.

http://image.guardian.co.uk/sys-files/Guardian/documents/2006/09/19/LettertoNick.pdf
(facsimile of the actual letter)

There is some point in scientists standing up to be counted on this one
rather than ceding the high ground to handful of ultraright US free
market think tank spokesmen who pretend that the science is unclear. It
is curious that extremes of left and right both deny climate science.

In the UK it was the right wing Tory Prime Minister Margaret Thatcher
that first put the issue on the agenda so we do not have the same rabid
political polarisation of the issue as in America.

But for reasons of "balance" TV debates frequently put up one denialist
and one mainstream scientist for a discussion without making it clear
that there is a big difference in the validity of their arguments. The
denialist arguments are well honed to appeal to the general public with
a cunning mixture of half truths and plausible lies. Pretty much the
same happens with UFO abductees - and the devil has all the best tunes.

I don't really like petitions, but scientists do have to stand up for
the truth. I am reminded of 100 authors against Einstein and his retort
"Why 100 authors? If I were wrong, then one would have been enough!".

Make no mistake NATURE will be the final arbiter on this issue.

Regards,
Martin Brown

With the regards to the same published people being involved with tobacco defenders
and being AGW skeptics, please do provide names and publications and dates. Please
note that the implication that science for hire can (and has been) be used against
AGW as well.

 

[Randy Yates]

Eric Jacobsen <eric.jacobsen@ieee.org> writes:

It's easy to be an armchair quarterback.

Amen, brother.

I suspect the biggest problem is that people here don't know what
they're talking about. It is virtually impossible for a product of this
type and application to have such a glaring oversight. For example,
perhaps the DOD made a tactical decision that, not only do they not CARE
if someone sees the video, it is actually encouraged. After all, if the
end effect is that the bad guys stop being bad, isn't that just as good
as them being dead?
--
Randy Yates % "And all that I can do
Digital Signal Labs % is say I'm sorry,
mailto://yates@ieee.org % that's the way it goes..."
http://www.digitalsignallabs.com % Getting To The Point', *Balance of Power*, ELO

 

[Jon Kirwan]

On Fri, 18 Dec 2009 11:03:12 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 18 Dec 2009 01:41:39 -0800, Jon Kirwan
jonk@infinitefactors.org> wrote:

On Fri, 18 Dec 2009 00:58:58 -0800 (PST), Bill Sloman
bill.sloman@ieee.org> wrote:

On Dec 18, 2:19 am, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

snip

Design any interesting circuits lately?

John's regular get out of jail free card, usually played after a long
post explaining why he is free to post denialist nonsense, while the
people who respond to point out that he doesn't know what he is
talking about should confine themselves to electronics.

I've been around the group long enough to have seen this card played
by John, time and time again. It's a highly predictable knee-jerk,
now. Rather than deal with his own overflowing ignorance.

Jon

Sloman is probably the single most-frequent poster to this group and
is literally 99% off-topic. And virtually every one of his posts
contains pompous insults. He is never helpful, never amusing, never
hopeful, never has ideas; he hasn't done interesting electronics in
decades and probably never will again.

Pick your friends as you will.

Who's picking friends here? I still suspect you were giving me a
bunch of bull about the holier-than-thou high road you want to take
here when you, on the same very day, continue the very thing you were
saying you don't want to encourage.

Jon

 

[Joel Koltner]

"Eric Jacobsen" <eric.jacobsen@ieee.org> wrote in message
news:%wSWm.5633$eH1.2611@newsfe16.iad...

I was addressing the link, not the cryptography. Most security people I've
worked with recognize that layering barries is usually a good thing, so why
use a standardized link that anybody can buy a receiver for when it's not
hard at all to obscure the link protocol?

I think the usual argument is the "chain is only as strong as its weakest
link" and "time is money" approach -- if you've selected, e.g., AES-256 as the
encryption algorithm, if there's someone who can manage to crack it in
real-time, you kinda have to assume they'll find decoding your proprietary
link protocol to be utterly trivial as well. Hence, it may not be worth the
extra time and expense to cook up your own new protocol -- especially when
you're paying for it with the taxpayer's money.

The other problem of is that there are plenty of cases where someone coming up
with a proprietary protocol unintentionally weakens the overall system
security by embedded something in plaintext that correlates with something in
the encrypted portion of the data packet. If you stick with well-known public
standards, there's usually a long track record of their vulnerabilities to
consider.

If you have really good crypto guys and plenty of money, I'd agree that
layering provides extra security. With the U.S. military, it seems to me that
the later is still usually not a problem, whereas the former sometimes is.

---Joel

 

[casual observer]

On Fri, 18 Dec 2009 16:48:25 -0500, Jerry Avins <jya@ieee.org> wrote:

The need to guard against cyberattacks on power stations and military
installations is a clear indication of bad -- make that stupid --
design. Critical facilities shouldn't share wire networks with
internet-at-large, and there would ideally be no radio links. Those who
don't like other people reading over their shoulders shouldn't build
glass houses.

Agreed. Get rid of the wireless links on the Predator drones and use
wired connections. Wait....huh? ;-)

 

[Vladimir Vassilevsky]

Jerry Avins wrote:

The need to guard against cyberattacks on power stations and military
installations is a clear indication of bad -- make that stupid --
design.

Big design can't be without stupid flaws, especially if that design is
done by big company. This is just the law of big numbers. Only the
simple things that were in production in large quantities and for many
years, can be cleaned to perfection.

Critical facilities shouldn't share wire networks with
internet-at-large, and there would ideally be no radio links. Those who
don't like other people reading over their shoulders shouldn't build
glass houses.

Recently I read that "Boeing 787 Dreamliner is safe against intended or
unintended cyberatacks, as its entertainment network is software
firewalled from the flight controls". Isn't it wonderful?

Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

 

[Eric Jacobsen]

On 12/18/2009 3:41 PM, Joel Koltner wrote:

"Eric Jacobsen" <eric.jacobsen@ieee.org> wrote in message
news:%wSWm.5633$eH1.2611@newsfe16.iad...
I was addressing the link, not the cryptography. Most security people
I've worked with recognize that layering barries is usually a good
thing, so why use a standardized link that anybody can buy a receiver
for when it's not hard at all to obscure the link protocol?

I think the usual argument is the "chain is only as strong as its
weakest link" and "time is money" approach -- if you've selected, e.g.,
AES-256 as the encryption algorithm, if there's someone who can manage
to crack it in real-time, you kinda have to assume they'll find decoding
your proprietary link protocol to be utterly trivial as well. Hence, it
may not be worth the extra time and expense to cook up your own new
protocol -- especially when you're paying for it with the taxpayer's
money.

The other problem of is that there are plenty of cases where someone
coming up with a proprietary protocol unintentionally weakens the
overall system security by embedded something in plaintext that
correlates with something in the encrypted portion of the data packet.
If you stick with well-known public standards, there's usually a long
track record of their vulnerabilities to consider.

If you have really good crypto guys and plenty of money, I'd agree that
layering provides extra security. With the U.S. military, it seems to me
that the later is still usually not a problem, whereas the former
sometimes is.

---Joel

Yet again, I'm not addressing the encryption, but the link (i.e., air
interface) protocol. Even in DVB-S and DVB-S2, the air interfaces are
completely independent from the transport layer and the encryption. If
you make the air interface just a bit pipe, it CAN'T expose the
encryption any more than any using a standardized air interface.

Making it difficult to even demodulate the signal, however, provides an
additional barrier to a would-be eavesdropper in that they must,
somehow, figure out how to demodulate the signal. This includes
figuring out the modulation type, the polynomial of the entropy
scrambler (NOT the same as encryption), the FEC, including any
polynomials, interleavers, or code matrices, any framing, etc., etc.,
etc. It's a monumental task if you don't also have a modulator with
which to perform detailed experiments, and even if you do the investment
and expertise required make it a pretty high hurdle.

Instead, they used DVB-S or DVB-S2, for which receivers are commonly
available.

Which is easier for eavesdropping?

--
Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.abineau.com

 

[Andrew Swallow]

krw wrote:

On Fri, 18 Dec 2009 02:08:44 +0000 (UTC), Rick Jones
rick.jones2@hp.com> wrote:

In comp.protocols.tcp-ip Mark <makolber@yahoo.com> wrote:
Passing encrypted video over a satellite network built for
unencrypted analog video is not a trivial challenge. As far as I
know, there exists no scheme to do this that has not been broken
already. The problem is that encryption works partly by diffusing
information so that no part of the output looks like any part of
the input. The satellite link is filled with errors and distortion
that have to be contained to retain adequate video quality.
um,, is that why General Instrument was able to do it did it 15 years
ago for HBO?
Is it "known" that the GI stuff (irony isn't cracked?

I don't believe anyone suggested using civilian encryption for
military applications, though it would have been better than nothing.

AES encryption would have probably beaten the Taliban and the Iranians.
Available in a single chip, or you can use software.

Andrew Swallow

 

[Joel Koltner]

Ah, sorry Eric, I was thinking you meant the packet transport protocol (what I
meant be tempted to call "link layer" but that's probably not correct) and not
the actual "physical" level link. My apologies.

Which is easier for eavesdropping?

DVB-S, certainly, although if they had used AES (ok, probably not available
when it was designed -- maybe 3DES?), they still would probably have been OK.

---Joel