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Status: Submitted 20000313
%t Distributed Computing Projects
%n ?R?
%s GIMPS, SETI@Home and Distributed.net Amongst Others
%a Alex Gough (alex@rcon.org)
%d 19991110
%d 20000310
%x Computers, Earth
%x RSA Broken By The Russians?
%k distributed.net, seti, aliens, computer, code,
mersenne, gimps
%e
Many people assume that their computer is always working as hard as it
possibly can. This is not true and most modern computers spend much of
their time waiting to be told what to do next. This is not an ideal
situation for a computer to be in as, although it cannot get bored, it is a
waste of its potential power. You might wonder just how much your computer
can do if this is all used. The answer is 'not a lot' but when N computers
all work together on the same task this becomes 'not a lot' * N which which
works out as being 'quite a lot really'.
This is similar to the proverbial piece of straw which broke the camel's
back except that here there isn't any straw and we don't have any camels.
To harness this latent power, various groups around the world have written
pieces of software which can be downloaded and run as a background process
in this idle time. Usually a central server will supply each client program
with a small chunk of data to work through then collect the results once the
client has finished.
Because different computers work at different rates they will complete a
given piece of work in different times. This allows for competitive
rankings, the formation of teams and detailed statistics about the project.
For some people the task they work on is less important than the amount and
quality of statistics they will be able to generate. Often people will
chose which project they assign their computer to on this basis.
So as to gain the maximum throughput of work units, the dedicated user will
leave their computer on all day and all night. This can be inconvenient
especially when the user has to sleep in the same room as a noisy machine
and also uses up a lot of power. Of course this power is all converted into
heat so can used instead of central heating for much of the year.
SETI@Home [1] is the best known of the distributed computing efforts. In
SETI@Home signals received by the Arecibo radio telescope are carefully
checked for even the slightest trace of an extraterrestrial broadcast.
SETI@Home is the most popular programme as it has a lofty goal with little
chance of success, making people side with the outside runner. Another
reason for its immense popularity is their ability to manipulate the media
to their own ends (which you would expect of an organization which exists to
listen to alien versions of 'Friends') and a very attractive front end
featuring all sorts of complicated graphics.
Distributed.net [2], also known as project Bovine (hence the cow logo),
allows its users to enter cryptography contests where a secret message is
encoded by another organization and the task is to search for the key which
will decode the data. Whoever finds the correct key normally gets a small
prize. The point of the contests is to show how weak most encryption
schemes are although it has taken the team more than two years to get only
18% through one of the competitions.
Distributed.net also runs a search for optimal golomb rulers (OGRs). An OGR
is the shortest ruler with a given number of marks on it such that no two
pairs of marks measure the same distance. Rulers like this are useful for
radio astronomy as the maximum amount of phase information (and thus detail)
can be gained when the receivers sit on the points of an OGR.
The Great Internet Mersenne Prime Search [3] or GIMPS for short is an
attempt to use the combined computing power of thousands of people to find
very large prime numbers. GIMPS uses algorithms which can only test primes
of the form (2^n)-1 where n is a prime, these are called Mersenne primes.
Prime numbers are used in cryptography, so in some small way the work of
GIMPS balances the work done by distributed.net . The Electronic Frontier
Foundation has put up a large prize for whoever discovers the first prime
number with over ten million decimal digits.
Of course you do not need to use a computer to participate in a distributed
project. For instance, if you went down to your local park with enough
friends and pairs of scissors, you would soon have the grass cut. If you
become fantastically rich then you might want to distribute your entire life
to other people. Have someone to clean your house, someone to dry your car
and even someone to sleep for you when you feel tired [4].
So what are you (and, more importantly, your computer) waiting for? Get
yourself a distributed application and you might become rich beyond your
wildest dreams (assuming that your dreams aren't _too_ wild of course).
[1] http://setiathome.ssl.berkeley.edu
[2] http://www.distributed.net
[3] http://www.mersenne.org/prime.htm
[4] The author is always open to offers of employment as a proxy sleeper.
%e
*EOA*
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