Web Directory

» 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.
   http://www.cs.uwaterloo.ca/~shallit/Papers/carissan.html

» FactorWorld
   Dedicated to algorithms and computational results on integer factorization. Includes links to papers, downloadable software, and online resources.
   http://www.crypto-world.com/FactorWorld.html

» Factoring Fermat Numbers
   Cash prizes for new factors of Fermat numbers Fn, for n = 12 through 22.
   http://www.perfsci.com/freegoods.htm#fermat

» Factoring Papers
   Links to papers on the theory and practice of factoring.
   http://www.crypto-world.com/FactorPapers.html

» Factoris
   Online calculator that factorizes large numbers, specified by formula.
   http://wims.unice.fr/~wims/wims.cgi?lang=en&module=tool/algebra/factor.en&cmd=new&

» Factorization Using the Elliptic Curve Method
   Java applet that can be used to find 20- or 30-digit factors of numbers or numerical expressions up to 1000 digits long. It also computes the number and sum of divisors, the Euler's totient and moebius functions, and the decomposition of the number in a s
   http://www.alpertron.com.ar/ECM.HTM

» Factorization of RSA-155
   Announcement of factorization of a 512-bit RSA key using the General Number Field Sieve (GNFS).
   http://www.crypto-world.com/announcements/RSA155.txt

» Factorizations of Near-repdigit Numbers
   Factorizations of numbers composed of all the same digit except first and/or last.
   http://homepage2.nifty.com/m_kamada/math/factorizations.htm

» Fermat Search
   Leonid Durman's Fermat number factoring site and program.
   http://www.fermatsearch.org/

» I Love Binary, Primes, and Factors
   Divisibility, primes and binary numbers.
   http://home.earthlink.net/~usondermann/binary.html

» Integer Factorization
   Paul Leyland's list of his own and other factorisations.
   http://www.leyland.vispa.com/numth/factorization/main.htm

» 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.
   http://amicable.homepage.dk/knwnc2.htm

» 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.
   http://www.rsasecurity.com/rsalabs/node.asp?id=2092

» 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.
   http://www.prothsearch.net/sierp.html

» The Factor Zone
   Aimed at grade school students and teachers, includes course guidelines, worksheets, and factor tables up to 600.
   http://factorzone.tripod.com/

» The XYYXF Project
   A collaborative project to produce the factorizations of x^y + y^x for 1<y<x<101.
   http://xyyxf.at.tut.by/