
View Poll Results: Factoring can be completed using Windows  
YES  2  15.38%  
NO  1  7.69%  
Depends  2  15.38%  
The question as stated is meaningless  8  61.54%  
Voters: 13. You may not vote on this poll 

Thread Tools 
20080320, 06:22  #1 
2·17·73 Posts 
Factoring Big Numbers In c#
We are working for Factoring Challenge of RSA .. We are using Grid Infrastructure with the help of Alchemi Middleware .. Alchemi Middleware uses C# Language .We have developed Class in c# which works for numbers less than 1024 bits..
We have to factorize n (of RSA) into p and q .. can anybody help me to start with project .. The class which we developed works for any number less than 1024 bits for any kind of simple arithmetic operations .. As we are using Grid Computing We need to create threads(Parallelize).. Which algorithm can i use for project .. Please give me links giving source codes of algorithms which works under windows platform .. 
20080320, 09:41  #2 
"Nancy"
Aug 2002
Alexandria
2467_{10} Posts 
The fact that you talk only about modular arithmetic suggests that you are not familiar with the Number Field Sieve, NFS, where highprecision modular arithmetic plays a relatively minor role in the computation.
Have you heard of NFS before? If not, I'd recommend "A Tale of Two Sieves" by Carl Pomerance as a very first introduction. Jason Papadopoulos (jasonp on this forum) has written a selfcontained implementation (at http://www.boo.net/~jasonp/qs.html) but it's not ready for 1024 bit GNFS. In fact, no software anywhere is  1024 bits can just barely be done with by SNFS these days (if you have acess to a large grid for several months), but is completely out of reach for GNFS. Alex 
20080320, 15:34  #3 
∂^{2}ω=0
Sep 2002
República de California
2×3^{2}×653 Posts 
Wasn't Java the last programming language that was going to make all these integer factorizations trivial to perform? Guess Sun decided there just wasn't enough money in it  or maybe RSA Labs paid them some side money to not put them out of business.
I mean, it *is* simply just an issue of being up on the latest "hipster language" being taught in Comp. Sci. courses, isn't it? "All these algorithmic problems go away if you just define the right class, overload a few operators, and deploy a functor in the right spot...and don't forget to keep your mutexes current..." In C++, I think one just needs to invoke the STL's builtin NFS utility like so: Code:
string input_number = "[insert your number in decimal form here]"; bool nfs_special = [set true to use SNFS, otherwise default to GNFS]; string list_of_prime_factors = string.run_nfs(nfs_special); 
20080320, 15:52  #4  
Undefined
"The unspeakable one"
Jun 2006
My evil lair
29×229 Posts 
Quote:
Code:
string input_number = "[insert your number in decimal form here]"; string list_of_prime_factors = input_number.factors(); 

20080320, 16:01  #5 
∂^{2}ω=0
Sep 2002
República de California
2·3^{2}·653 Posts 
Even better  just overload the "" so that it triggers the snfsorgnfs preprocessing parser, and overload the assignment operator so the = ... initialization triggers the factorization. I'd code it and take all of the RSA prize money, but I'm too lazy.
Last fiddled with by ewmayer on 20080320 at 16:02 
20080320, 16:06  #6 
Undefined
"The unspeakable one"
Jun 2006
My evil lair
29×229 Posts 

20080320, 16:07  #7 
∂^{2}ω=0
Sep 2002
República de California
2·3^{2}·653 Posts 

20080320, 16:17  #8 
Undefined
"The unspeakable one"
Jun 2006
My evil lair
14761_{8} Posts 

20080320, 16:26  #9  
Tribal Bullet
Oct 2004
2·5^{2}·71 Posts 
Quote:
Last fiddled with by jasonp on 20080320 at 16:30 Reason: change link to avoid registration and 404 from ibm.com 

20080320, 16:36  #10  
∂^{2}ω=0
Sep 2002
República de California
2·3^{2}·653 Posts 
Quote:
BTW, is that crowd substantively different than the "teaming screenage girls"? I used to chat online a lot with the latter until one of them turned out to be a hairyknuckled middleaged FBI agent ... but enough about my adventures in online dating... 

20080320, 17:17  #11  
"Bob Silverman"
Nov 2003
North of Boston
7496_{10} Posts 
Quote:
The "RSA Factoring challenge"................... ..................was withdrawn some time ago. It no longer exists. 

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Some code for factoring numbers up to 2^63  arbooker  Factoring  219  20221028 13:48 
Factoring Mersenne numbers  paulunderwood  Miscellaneous Math  18  20170827 14:56 
Factoring Fermat numbers  siegert81  Factoring  12  20110203 13:55 
Need help factoring Cunningham numbers  jasong  Factoring  27  20060321 02:47 
Factoring Fermat Numbers  Axel Fox  Software  14  20030704 18:57 