Pyecm

Pyecm factors large integers (up to 50 digits) using the Elliptic Curve Method (ECM), a fast factoring algorithm.

Pyecm was a high-school project for myself (Martin Kelly) and my friend, Eric Larson. Eric did more of the math and I did most of the code. Although the code is not very clean by my standards today, it works and is quite fast. It was also a nice illustration of how Python can be used for performance-critical code, if the bottlenecks are clearly identified and implemented in C. In our case, we do this via the wonderful gmpy.

How to run pyecm

All platforms

• First, make sure python (>= 2.3) is installed and working. You can always get the latest release from http://python.org
• For speed increases, you may optionally install gmpy and/or psyco. Both are highly recommended, especially gmpy, as they result in massive speed increases.

Unix, Linux, Mac

• You can either use python pyecm.py to run it or change the filename to pyecm and execute it as a script.

Windows

• Just run pyecm.py as you would any other python program.

Related projects

• Old home for pyecm on Sourceforge (https://sourceforge.net/projects/pyecm)
• gmpy (https://github.com/aleaxit/gmpy)
• psyco (http://psyco.sourceforge.net/)