What is yEnc ?
yEnc is a new encoding method which offers efficient and
proper transmission for binaries on the Usenet (or by eMail and other applications).
Other encodings are BASE64, BinHex, UUencode, Quoted Printable, .....
yEnc is NOT an audio format (as MP3) or a video format (as
AVI, MOV,...) or a picture format (as GIF or JPEG).
What is an encoding - and why is it used ?
News and Mail transfer require that a binary attachment is
"encoded" before it is sent. And they are "decoded" after they have
been received. Normally all this is done by your newsreader (or mail-program). You dont
see it. Most dont even know it.
The encoding is necessary because the special methods for
the transfer of news & mail (protocols) require it. A message with a binary which is
not encoded is corrupted during transmission - or transmission is denied at all.
Transport of messages by News and Mail was restricted to
US-ASCII characters when the protocols were written (20 years ago). These services have
been created to transport only plain US-text. Special characters (control-characters,
symbols, non-US-characters) were forbidden - and used for special purposes. But because
people wanted to send also binary attachments by News and Mail some 'tricks' were
implemented: The binary was changed to "allowed US-ASCII-characters" before
transmission (encoding) - and back to a binary after transmission (decoding). The usual
encoding methods are still respecting these old limitations - and are used everywhere.
Unfortunately there is a price for this 'trick': Encoding makes a message longer. And not
just a little, but 33%-40% longer than the original attachments. This results in 33%-40%
more bytes for a message - 33%-40% more time for the transmission - 33-40% more diskspace
on the harddisk where there messages are stored (on news- and mail-servers).
Meanwhile Usenet is able to to transport more than
"US-ASCII", it could also transport other characters. Just a few special
characters are still forbidden. Unfortunetaly the encodings were never changed. We are all
still using BASE64, BinHex, UUencode. We are all wasting every day bandwidth, time,
diskspace and money.
yEnc is now a proposed encoding method which is using the
fact that news-servers can today transport binaries more efficient. On eMail the situation
is far more complicated because there are a lot of older programs and computers involved.
But also there would be potential for savings.
The naming - yEnc ?!
You might ask why the name of this thing is
"yEnc" - yEncoding, yDecoding.
Well - I did introduce the name "MyNews" for another project (in 1997) long
before everybody began to use My-Xxxx for his services or domain names. When I designed
the new encoding I needed any name for it. But as all the 'MyXxxx' names were already in
use (so I could not use MyEnc). I wanted a new name - which is nearly unique on the
Internet. The name "yEncode" was never used - and the short form would be yEnc.
The file-extension *.ync would also be unique - so I found a short and good
name.
Jurgen Helbing - 06. March 2001
