brainstorming: which formats to use and which to avoid

Werner Koch wk at
Mon Jun 11 12:22:16 UTC 2001

 || On Mon, 11 Jun 2001 12:49:20 +0200
 || piccardi at (Simone Piccardi) wrote: 

 sp> The Ogg format (Vorbis and Tarkin) and html are the only data format
 sp> that I know to be patent-free (but I'm not an expert). Probably you

We will never be able to decide whether something is patented; this is
_one_ of the major problems with software patents.  They are written
in a language to cover the real claims.

What we should do is to put formats with known patents claims on a
black list.

What I tried to express in my previous mail was, that even that Ogg is
a free and fully documented format, some vendor might go and add a
proprietary extension to it like Microsoft did it with Kerberos.

Avoiding this pitfall is easy by telling the URL or the RFC of the
specs and warning about possible non-compliat implementations.

Let's keep the patent discussion out except for well-know cases and
concentrate on format defintions.  To start with some formats you just
have to go through the RFC marked as Standards or Draft-Standards.

Hmmm, here are some things which come to mind:

Compression - Whitelist

  ZIP as defined in RFC 1950, 1951, 1952 
  BZIP2 as defined in the documentation (URL)

Compression - Blacklist

  Compress (*.Z) due to the use of the LZW algorithm
  ARR   defined but patented
  PkZip uses patented algorithms

Audio - Whitelist

  WAV as defined by some Micrsoft documentaion 
  Ogg as defined in the documentsion of the software

Audio - Blacklist

  MP3 due to [patent claims by Fraunhofer

Images - Whitelist

  JPEG as defined by the Joint Photographers Expert Group without the
       option for Digital Encoding
  PNG  as defined in RFC????

Images - Blacklist

  GIF  due to the LZW patent and becuase PNG superior to it.
  TIFF because it is a collection of different algorithms

Documents - Whitelist

  Postscript according to Adobe specs xxx
  PDF   according to specs ... but w/o the options ...

Documents - Blacklist

  MS Word  - no complete specification
  Adobe Illustrator - proprietary Postscrip extensions

Vector Graphics - Whitelist

  fig  as specified in the fig documentation
  SVF??? (the Web Vector format) as specified by the W3C 

Vector Graphics - Blacklist

  Flash [I am not sure whether this is sufficiently documented]
  Corel not documented

Character Encodings - Whitelist


Character Encodings - Blacklist

  ISO646 (?) encodings of some characters depend on the locale
  EBCDIC due to many different variants

Crypto protocols - Whitelist

  OpenPGP ;-)
  Kerberos [but watch out for MS extensions]

Digital Signature Certificates - Blacklist

  X.509 - too many different profiles, proprietary extensions or
          widely used wrong implementations.
  PPTP   and many, many other insecure and undocumented protocols.



Werner Koch        Omnis enim res, quae dando non deficit, dum habetur
g10 Code GmbH      et non datur, nondum habetur, quomodo habenda est.
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