[p2p-hackers] Online Codes

[mgp at ucla.edu]

Hi Nick,

First, I think your optimization to rateless codes is interesting,
although I'm worried that it might not be 
computationally feasible. I haven't given it much thought yet, but at
first glimpse it seems like it would take 
exponential or factorial time to come up with such shortcuts from XORing
the check blocks. I'll give it more 
thought, but if you or anyone else can show it can be done efficiently, I 
will be pleasantly suprised :)

About your second e-mail... On the web site www.rateless.com, if you go
to Library, you will see that under 
the "Online Codes" paper it says:

"This paper marked the beginning of Rateless Research. The codes
described in it fall within the scope of 
patents owned by Digital Fountain, Inc. In order to prevent intellectual
property overlap, we have 
developed and use a new class of practical rateless codes, based on
decoders that don't use chain-reaction, 
message passing or belief-propagation techniques."

Which, I think, means that the rateless codes method described in the
paper is not the one they are 
currently using, for the one in the paper is covered by the patents of
Digital Fountain, Inc. Also, in the 
excellent paper "Digital Fountains: A Survey and Look Forward" [1], under 
"Barriers to Adoption -- Patent 
Protection" you will find references to 10 (!) or so patents in the
bibliography. Again, most of these I believe 
belong to Digital Fountain, Inc.

Regards,
Michael Parker

[1] www.eecs.harvard.edu/~michaelm/postscripts/itw2004.pdf


On Mon, 21 Feb 2005 16:23:12 +1300 Nick Johnson wrote:

> On 15/02/2005, at 10:52 PM, Michael Parker wrote:
> 
> > Hi all,
> >
> > Does anyone know what happened to the "Online Codes" Sourceforge 
> > project, listed at http://sourceforge.net/projects/onlinecodes? I'm 
> > asking here for two reasons: First, because Online Codes [1, 2] would 
> > be a great tool in peer-to-peer applications, so I thought someone 
> > here might have followed the project while it was still active. 
> > Second, I've written a solid library implementation of the Online 
> > Codes encoding/decoding algorithm described in the aforementioned 
> > papers. Alas, only after I implemented it did I find out that the 
> > authors' company, Rateless, had patented it (or, so they allude to on 
> > their web site www.rateless.com, Digital Fountain owned the IP).
> 
> I don't see it - where do they allude to it?
> The only mention of patents google finds on the site is in the copy of 
> the GPL they have hosted there.
> 
> -Nick Johnson
> 
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