Sorry, but your link had no references to bit rates on it whatsoever.
Bullshit. First off, your adjective constitutes an oxymoron.
BICO capacity for R = 1/2 is at about 0.177dB Eb/No, and for R = 1/3
Government has sued Boeing for fraud:
Disillusioned, yes. Angry for being excluded? No.
Well, that's what GAO said about the people running JTRS, that they do
Hmm...my guess is that mission critical means that it should not:
Neither is 2Mb/s. And JTRS is struggling to get that.
Tail wagging the dog.
Using antiquated technology. There does exist technology that allows a
They need to stop thinking in "waveforms" and start thinking in
Well, jamming is always possible. This is why some missiles are guided
Adding a bi-directional end-to-end crypto system would stop that.
Every report that I have ever read about JTRS by oversight committees
Military is still using same radios they were using 15 years ago, and
Oh they work. There is no doubt in my mind that they work.
Doh! I think I went the wrong way with the 3db and 4.77dB differences.
I'm less skeptical now.
http://www.armytimes.com/news/2008/01/army_bandwidth_080121w/
Yer nuts.
You have no clue what is involved.
*trillion years.On Dec 20, 12:29 pm, Tom Gootee <t...@fullnet.com> wrote:
On Dec 19, 11:01 pm, Le Chaud Lapin <jaibudu...@gmail.com> wrote:
On Dec 19, 9:02 pm, Tom Gootee <t...@fullnet.com> wrote:
On Dec 18, 3:22 pm, spop...@speedymail.org (Steve Pope) wrote:
Eric Jacobsen <eric.jacob...@ieee.org> wrote:
On 12/18/2009 1:55 AM, Steve Pope wrote:
Le Chaud Lapin<jaibudu...@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
I think that he did mean what he said, that EVEN cracking it in NON-
real-time is also impossible. However, that's probably wrong.
Someone told me that the time it takes to crack it might be down to
about 40 years or so, nowadays.
That's what I meant, but whoever told you 40 years probably needs to
do a little more work with crypto.
Unless the fundamental AES algorithm is cracked, a determination not
yet made by the top cryptographers in the world, no one will be
cracking 256-bit AES any time soon.
A attempted brute-force attack on 256-bit AES would border on
insanity.
See the following link:
http://www.nist.gov/public_affairs/releases/aesq&a.htm
"Assuming that one could build a machine that could recover a DES key
in a second (i.e., try 2^55 keys per second), then it would take that
machine approximately 149 thousand-billion (149 trillion) years to
crack a 128-bit AES key. To put that into perspective, the universe is
believed to be less than 20 billion years old."
That's 128-bit AES. I leave it to the reader to figure out how long it
would take to brute-force search on 256-bit AES.
Hint: It's greater than 149 trillion years. Add 30+ zeros.
Also note in the paragraph above that 2^55=36,028,797,018,963,968, so
this is a conservative proposition. You're talking about a machine
that can do 36 quadrillion decipherments per second. Having every
computational device on the planet at one's disposal would help a
little bit, but you're still talking about billions of trillions of
quadrillions of...yada..the age of the universe.
-Le Chaud Lapin-- Hide quoted text -
- Show quoted text -
How do you calculate those times?
Let's see. Just optimistically assuming that we could try 2^64 keys
per second, for simplicity, and that we have a 128-bit key, that would
take 2^64 seconds, since there would be 2^128 possible keys of 128
bits, and (2^128 keys) / (2^64 keys/sec) = 2^(128-64) seconds = 2^64
seconds. There are 60*60*24*365.25 = 31.5576x10^6 seconds per year..
If I "round that off" to 30x2^20 (= 31.45728x10^6), then it would take
2^64 seconds / (30x2^20 seconds/year) = (1/30) * ((2^64)/(2^20) > > (2^44)/30 = (1/3)(2^43) years. I must have made a math error, because
that's a lot longer than 149 trillion years. It looks more like the
256-bit crack-time that you gave.
However, I have almost no idea how many keys per second could be
tried, by a large, well-financed, tech- and crypto-savvy adversary.
That is the key (pun intended). But it looks like it would be a lot
cheaper for them to just buy or steal the key.
Cheers,
Yes, the money is best spend trying other things.
Assuming 2^64 crypto operations per second, 128-bit crack would take,
in years:
2^64/2/amount-of-time-in-year.
You have to do / 2 on bit-width to eliminate half the key space. The
right key will either be in upper-half of keyspace or the lower-half.
If you check only lower-half, sometimes you will get lucky, sometimes
not, so on average, you check half the keys.
Continuing...
2^64/2/60/60/25/365 = 292,471,208,677 years.
But this assumes 2^64 ops/second. NIST only claimed 2^55 ops per
second. That's 9-bits slower, or 512 times slower, so to get their 149
trillion ops per second*, we do:
292,471,208,677 * 512 = 149,745,258,842,898.
Agree
Correct; as one gets into lower code rates, going to even lower rates
Actually it's about -1.7 dB, but let's say it's -1 for the
I'm not too skeptical. I would posit that GSM phones in their
Well, it IS used for things other than magnets. To be pedantic it's *enamelled* btw.
Or both.
Except SvS was funny.krw wrote:
On Sun, 20 Dec 2009 12:29:48 -0800, Son of a Sea Cook
NotaBrewster@thebarattheendoftheuniverse.org> wrote:
On Sun, 20 Dec 2009 10:30:29 -0800 (PST), Le Chaud Lapin
jaibuduvin@gmail.com> wrote:
It took them 6 years and $11 billon to discover this,
You're an idiot. The system is working. You just cannot handle the
fact that it is.
Wow! A DimBulb six-pack spotted! While certainly not unheard of
(seven is still the record, I believe), you don't see these every day.
These two are like a bad episode of 'Spy VS Spy' in a '60s Mad
magazine.