Discovery of a Lost Factoring Machine
Built by a French amateur, E.-O. Carissan, around 1919. Shallit, Williams and Morain include photographs and references to their paper. |
Factoring Fermat Numbers
Cash prizes for new factors of Fermat numbers Fn, for n = 12 through 22. |
Factoring Papers
Links to papers on the theory and practice of factoring. |
Factoring Theory
A thorough summary of many major factoring algorithms. Includes some source code on many pages, and gentle introductions to the more complex methods. |
Factoris
Online calculator that factorizes large numbers, specified by formula. |
Factorization of F10
F10 = 2^(2^10) + 1 is the 10-th Fermat number. Richard Brent details his discovery of the two largest factors. |
Factorization of RSA-155
Announcement of factorization of a 512-bit RSA key using the General Number Field Sieve (GNFS). |
FactorWorld
Dedicated to algorithms and computational results on integer factorization. Includes links to papers, downloadable software, and online resources. |
I Love Binary, Primes, and Factors
Divisibility, primes and binary numbers. |
Known Amicable Pairs
A listing of all the known pairs of numbers, each of which is the sum of the aliquot divisors of the other. Complete for smaller numbers, and extending beyond 200 digits. |
N!+-1 Factoring Status
Factoring efforts that have been made so far on numbers of the form n!+-1 using ECM factoring. |
Number Field Sieve
Triade systems links to papers on the number field sieve. |
Proth Factors
The current search status for factoring Proth numbers (k.2^n+1). |
Robinson Primes
An analysis of problems relating to the numbers k.2^n+-1, primes, and factor patterns, including the Sierpinski problem. |
RSA Laboratories Factoring Challenge
Numbers representative of those used in the RSA cryptosystem are offered for factor attempts with prizes. A Partition List challenge is also provided in order to encourage work on factoring in general. |
Sam Wagstaff
Article about SNFS factorisation of 3^349-1. |
Sierpinski Problem
Sierpinski proved there exist infinitely many odd integers k such that k*2^n+1 is composite for every n. Ray Ballinger coordinates a search to prove or disprove whether k=78557 is the smallest solution. |
The Anti-Divisor
A definition and description of the Anti-Divisor, and some related results. |
The Factor Zone
Aimed at grade school students and teachers, includes course guidelines, worksheets, and factor tables up to 600. |
The XYYXF Project
A collaborative project to produce the factorizations of x^y + y^x for 1<y<x<101. |
