Re: Breaking Huffman Codes

From: DSCOTT (daVvid_a_scott_at_email.com)
Date: 05/31/03 

Date: 31 May 2003 13:10:54 GMT

bill@nedell.com wrote in
<c9089864.0305310422.3184281b@posting.google.com>:

>Mok-Kong Shen <mok-kong.shen@t-online.de> wrote in message
>news:<3ED774E2.6974F2D6@t-online.de>...
>> bill@nedell.com wrote:
>> >
>> > > What are you doing with that data? Are you trying to analyze an
>> > > actual plane crash? Do you have the box in your possession, or
>> > > just the data?
>> >
>> > We provide quality assurance data analysis services for airline
>> > customers.
>> >
>> > I don't have routine access to flight data recorder hardware. I do
>> > have samples of compressed and decompressed files and I've written a
>> > decoder to experiment with. So far no luck.
>>
>> I believe you would have quite a hard time. Is it sure
>> at all that Huffman compression and not some other
>> compression scheme is involved?
>
>I forgot to mention that the flight data recorders we are analyzing
>are made by L3 Communications (
>http://www.l-3ar.com/html/av_products.html ), models F1000 and FA2100.
>I'm hoping someone out there will know for sure what compression
>scheme these boxes use.
>

  Why the reluctance on giving even sample data? You claim you have
raw data and compressed data. How did you get this. Do you have
a device that compresses it for you or what?

David A. Scott 

-- 
My Crypto code
http://cryptography.org/cgi-bin/crypto.cgi/Misc/scott19u.zip
http://cryptography.org/cgi-bin/crypto.cgi/Misc/scott16u.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"

Relevant Pages

  • Re: More of an Algorithems question
    ... >> Yes, I saw that the two 1-bit files were a problem as far compression, ... Yes, as you suggest, any permutation on the set of n-or-less bit files ... can be used to define a compression scheme. ...
    (sci.math)
  • Re: how do I do DCT on a 100x100 image?
    ... huhua wrote: ... lower frequencies less and usually leaves the DC element alone). ... compression techniques which are usually lossless. ... typical compression scheme you will get much greater data ...
    (comp.dsp)
  • Re: Optimize file
    ... not supported (has to do with compression scheme used LZW ... apps I have on my PPC. ... support for them was simply dropped from PPC image viewers ...
    (microsoft.public.pocketpc)
  • Re: Data encryption 360 degrees the nsa cannot break -- 01
    ... :_very_ good compression ratio would be 10000:1. ... An *average* lossless compression ratio of 10000:1 is not possible. ... Examined over all possible input files, no compression scheme can ... But that's over all possible input files. ...
    (comp.security.misc)
  • Re: compression API available in Java & C++?
    ... > I'm looking for a compression algorithm that works better than gzip ... No general-purpose compression scheme is going to be very much help for such ... The gzip compression scheme can be pre-trained ...
    (comp.lang.java.programmer)