brainstorming: which formats to use and which to avoid
Werner Koch
wk at gnupg.org
Mon Jun 11 12:22:16 UTC 2001
|| On Mon, 11 Jun 2001 12:49:20 +0200
|| piccardi at firenze.linux.it (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
US-ASCII
UTF-8
ISO-8859-*
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]
SSH
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.
ciao,
Werner
--
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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