[RC5] Secret-Key Challenge status

SideWinder sidewinder at kolumbus.fi
Wed May 23 17:24:42 EDT 2007

Hash: SHA1

Coran Fisher wrote:
> In the ancient texts SideWinder wrote:
>> simulation, climate simulation, NEO tracking, etc.). Can Dnet really 
>> point to an obvious immediate use of confirming the shortest known 25 
>> mark ruler, or even finding a shorter one? Will someone actually change 
>> their practical applications, if a shorter ruler is found today?
> I am extremely ignorant of Optimum Golum Rulers and their practical
> applications but I just thought I'd start with a Wikipedia article.
> If you look at http://en.wikipedia.org/wiki/Golomb_ruler 
> "One practical use of Golomb rulers is in the design of phased array
> radio antennas such as radio telescopes. Antennae in an [0,1,4,6] Golomb
> ruler configuration can often be seen at cell sites."
> Someone more knowledgable can give more information I'm sure but I hope
> that gives you a starting point.

I haven't been able to find any information of a practical use for a 25 
mark ruler specifically. I don't believe that the applications for 
example of 4 mark rulers would benefit from an improved 25 mark ruler. I 
could be completely wrong of course (and actually I kind of hope that), 
but I think it would be a part for the Dnet folks who write project 
documentation to dig into that.

Now the introduction only contains very general references of what OGRs 
could be good for ("OGR's have many applications including sensor 
placements for X-ray crystallography and radio astronomy. Golomb rulers 
can also play a significant role in combinatorics, coding theory and 
communications"), but nothing particular to how this 7 year long project 
could advance the field when actually completed.

I understand it's possible that no practical uses for this information 
have yet been identified, placing it only inside basic research. 
However, if some such planned or even potential uses have been 
identified, for example since OGR-25 started, then the project 
description should definitely have more information about them.

- -- 

 >------->- SideWinder -<-------<

PGP key ID: 0x77CCE3D6

___Computer Science: solving today's problems tomorrow.

Version: PGP Desktop 9.6.1 (Build 1012)
Charset: ISO-8859-1


More information about the rc5 mailing list