ECM client/server

The Goal

The ECM project has been up and running for some time. It's goal is to factor large composite numbers using the ECM method. ECM is a highly efficient method of finding prime factors in the 35-55 digit range.

Additional Information

The software
The software available here contains a client-server wrapper for running the ECM search program. It is designed in such a way that it can be installed once, and then ignored. It will quietly use otherwise wasted resources on your machine to perform its search. There is virtually no impact on other processes that may be running on your machine.

The most recent package available is version 2.0k. It was released on June 21, 1999. Source is included in this file.

Getting started
To get started, do the following:

Where to connect to
Paul Leyland has volunteered to host a server. Its address is (port 8194). The machine may change, but please point your client at this server (check back here for updates if it stops working).

Your own server
It's possible to run your own. There are a couple of reasons you might want to do this. FIrst, you may not want to work on the fame composites as the larger group. Second, you may want to limit outbound connections (firewall issues, for example). If you want to run your own server, see the detail page and the server subdirectory in the downloaded zip file.

Factors found so far
I found a factor with this setup even before I released it. The following file is an up-to-date list of everything found that was turned in so far. factors.html.

This page has been accessed

times since September 15, 1998.

Questions / comments / changes? Please contact me at