-----BEGIN PGP SIGNED MESSAGE----- Just saw this on Usenet, was wondering who knows this guy. Obviously not a cpunk or it would have hit the list right away. Not in the mood to run code on my account without knowing that I know what it will do. From: bobs@mathworks.com (Bob Silverman) Newsgroups: sci.math,sci.crypt,alt.security.pgp,sci.math.num-analysis,comp.arch.arithmetic Subject: Factoring Code Date: 13 Sep 1995 09:22:38 -0400 Organization: The MathWorks, Inc., Natick, MA 01760 Lines: 41 Distribution: inet Message-ID: <436luu$3lu@puff.mathworks.com> NNTP-Posting-Host: puff.mathworks.com Several people have requested factoring code recently. After thinking about it I have decided to offer a deal. I do not have the machine resources I once had, and have some numbers that I would like factored. They are in the 80-90 digit range. My code will do an 85 digit number in about 500 hours on a single Sparc-10. The code is perfectly parallelizable, so 40 machines will do 85 digits overnight. Run time for QS can vary by a factor of 2.5 depending on how "rich" the number being factored is in small quadratic residues. I will make available my complete Multiple Polynomial Quadratic Sieve code, along with instructions, to anyone who will factor at least one of these numbers. This code includes the siever, the code to combine large primes, the matrix solver (a naiive Gaussian elim over GF(2), but one which solves a 25K x 25K system in 15 min on a single Sparc), and the code to multiply everything together and find the factors. I will also throw in a routine which reads the output file and scans for bad relations. Sometimes, when running on many machines, I/O errors creep into the output files. A machine can go down when writing a record, or there can be a network problem etc. I also have a program which excizes bad records in the output files And one which sets up multiple sub-directories with the proper data files so one can run in parallel. Also included is a program which scans the output files in these multiple sub-directories and counts the number of relations found. There is also a program to predict (fairly accurately!) how close to done you are based on output from the counting program. This code will also include a decent collection of fast, very portable multiple precision routines. All this is for the taking if you guarantee to factor just one number for me. - -- Bob Silverman The MathWorks Inc. 24 Prime Park Way Natick, MA -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQB1AwUBMFd5fsLa+QKZS485AQELHAL/QS2LizHGSzT7h3b8cU78GiR9QLoaQ6zf FEEyt8XRDFqlUe7CKFfDKB1SPPviAZeBPM4XDfswfvfXpKNLamZQUNc7VYgzPIC0 3knFeQf2A/zWuGBZQp/TM0xBcwKW5lW7 =Zyke -----END PGP SIGNATURE----- <don@cs.byu.edu> fRee cRyPTo! jOin the hUnt or BE tHe PrEY PGP key - http://bert.cs.byu.edu/~don or PubKey servers (0x994b8f39) June 7&14, 1995: 1st amendment repealed. Death threats ALWAYS pgp signed * This user insured by the Smith, Wesson, & Zimmermann insurance company *