Google Summer of Code: Mozilla Projects

Posted Aug 23, 2007 15:28 UTC (Thu) by zooko (guest, #2589)
Parent article: Google Summer of Code: Mozilla Projects

The idea of a link fingerprint (this is the first that I've heard of it), is an example of a self-authenticating identifier. I wrote an essay which made a lot of people aware of this concept:

https://zooko.com/distnames.html

Other examples are Freenet's content-hash-keys (CHKs), which are equivalent to link fingerprints, and Freenet's sub-space keys (SSKs), which are more flexible in that they allow the file being identified to change without changing the identifier. David Maziere's research on "the self-certifying file system" contained an equivalent to SSKs. Mark S. Miller's research on Pet Names was what inspired my "distnames" essay in the first place, and it contains the most complete proposal for making identifiers both secure and user-friendly:

http://www.skyhunter.com/marcs/petnames/IntroPetNames.html

Phil Zimmermann's Zfone secure phone includes a similar technique (due to my suggestion), called "Sticky Note Security".

My current free-software project, http://allmydata.org, contains equivalents to both CHKs and SSKs.

I'm very glad to hear about this project in Mozilla. The idea of using CHKs to denote immutable contents is long overdue -- we should have done this at the beginning of the web. Furthermore, the idea of using SSKs to denote mutable contents may be coming due, too.

--Zooko

Google Summer of Code: Mozilla Projects

Posted Aug 23, 2007 21:59 UTC (Thu) by bronson (subscriber, #4806) [Link] (3 responses)

Nobody's using jpeg2000 because it's full of patent landmines. Nobody wants to be the first to get sued. Since the quality isn't THAT much better anyway, there's really no good reason to change.

Standards writers, let jpeg2000 be a lesson! If you don't spend enough time worrying about patents, all your work might be for naught.

Personally, I think jpeg2000 is DOA forever. I look forward to when png2000 gets developed though!

jpeg2000

Posted Aug 24, 2007 7:59 UTC (Fri) by eru (subscriber, #2753) [Link] (2 responses)

I think jpeg2000 is DOA forever.

Since the lifetime of patents is just 20 years, it might see some use after 2020...

jpeg2000

Posted Aug 26, 2007 0:31 UTC (Sun) by riddochc (guest, #43) [Link] (1 responses)

...Assuming someone won't come up with something better and patent-free in the meantime. There are probably *already* other formats better than jpeg2000, not including any developments in the next 13 years...

jpeg2000

Posted Aug 30, 2007 4:39 UTC (Thu) by roelofs (guest, #2599) [Link]

There are probably *already* other formats better than jpeg2000, not including any developments in the next 13 years...

Hell, in my experience, regular JPEG is better than JPEG-2000, both quality-wise and size-wise, and what I found online (real users, not researchers or graphics-tools vendors) completely agreed with that assessment.

Of course, it could be that the encoders for images in question just sucked massively, but it seems odd that all of them should be so bad--particularly when they're being held up as examples of JPEG-2000's quality. If you like grass that looks like split-pea soup, OK, maybe JP2K is just what you're looking for...but I prefer to see the blades.

I'd love to hear about exceptions, preferably involving publicly available images (the JPEG-2000 and lossless versions, at a minimum; I can create my own JPEG-1991 [or whatever] images at arbitrary quality settings).

Greg