mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > FactorDB

Reply
 
Thread Tools
Old 2016-01-30, 23:07   #1
labba
 
Jan 2016

1 Posts
Default RSA multi factor

hi,
i have used the YaFu and entered a N of an RSA and it solved it by giving me back 15 primes... how can i continue from this point on to break the small RSA key that i have ?
labba is offline   Reply With Quote
Old 2016-01-30, 23:19   #2
Mini-Geek
Account Deleted
 
Mini-Geek's Avatar
 
"Tim Sorbera"
Aug 2006
San Antonio, TX USA

17·251 Posts
Default

Are you sure you've got the right N? Any good key choice (if not any valid key, if this article's offhand comment is right) will be a semiprime, not consist of 15 primes.

Anyway, once you've got the right number factored, this post from StackOverflow goes into (the mathematical side, not a script or anything) how to calculate the private key. The most important part is this: (d is the private exponent, e is the public exponent, n is the public key, n is semiprime with factors p and q)

Code:
d = e^-1 mod phi(n)
  = e^-1 mod (p-1)*(q-1)
(note that if you don't have a semiprime, the phi calculation gets more complicated)

Then you just need to compute that modular multiplicative inverse, convert the number into a usable format (hex?) and use it.

Last fiddled with by Mini-Geek on 2016-01-30 at 23:28
Mini-Geek is offline   Reply With Quote
Old 2016-01-30, 23:25   #3
wombatman
I moo ablest echo power!
 
wombatman's Avatar
 
May 2013

33078 Posts
Default

Sounds like a Teslacrypt infection. You may wish to head over here if that's the case: http://www.mersenneforum.org/showthread.php?t=20767
wombatman is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
multi-core TF dbaugh Information & Answers 3 2011-09-06 01:32
Multi-threaded factoring bchaffin Aliquot Sequences 8 2010-10-24 13:38
Multi-Core / Multi-CPU Assignments (missing) worknplay Software 3 2008-11-05 17:26
Dual (or multi) motherboards? uigrad Hardware 16 2008-10-18 08:36
Multi CPU installation using GUI client ? willy1 NFSNET Discussion 5 2004-03-18 13:19

All times are UTC. The time now is 01:50.

Tue Nov 24 01:50:34 UTC 2020 up 74 days, 23:01, 4 users, load averages: 2.76, 2.67, 2.62

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.