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2015-07-17, 15:31   #34
VictordeHolland

"Victor de Hollander"
Aug 2011
the Netherlands

49B16 Posts

Quote:
 Originally Posted by Jayder Here is another interesting one. I have recently stumbled onto this C81 (link). This will be a difficult one to crack. In fact, it will likely take longer than the age of the universe to factor.
I hope you meant it ironically?

 2015-07-17, 16:14 #35 petrw1 1976 Toyota Corona years forever!     "Wayne" Nov 2006 Saskatchewan, Canada 52×211 Posts Same person finds different factor via ECM and PM1 on the same day Code: Mn Status Details 131009 Factored 1937759097343 15368075063617012721 469572650565399789119183 251874321670721973902750994646081 History Date User Type Result 2015-07-17 BloodIce F-ECM Factor: 469572650565399789119183 / (ECM curve 99, B1=250000, B2=25000000) 2015-07-17 BloodIce F-PM1 Factor: 251874321670721973902750994646081 / (P-1, B1=50000000) 2009-03-05 ANONYMOUS F-ECM Factor: 15368075063617012721
2015-07-17, 18:53   #36
Jayder

Dec 2012

32·31 Posts

Quote:
 Originally Posted by VictordeHolland I hope you meant it ironically?
I hope so.

 2015-07-17, 21:46 #37 storflyt32   Feb 2013 49110 Posts Hi, Jayder. Try multiplying Mersenne 48 with the factor 3, next try factorizing the number you get. It should not be that difficult. If I happen to multiply a known RSA factor with a Fermat factor, I might end up at a number like this, 19036657588412969111505965532704495313206606970654378333477575250997660572 96146492268504477755829049148371391847449774943227537240957345732440163922533773 3449295565780737 It is a C170, by the way. Try factorizing this number. Based on the information given, it should not be an impossible thing to do. Edit: I only read page 3 here before posting. The last page for some reason slipped my fingers. Last fiddled with by storflyt32 on 2015-07-17 at 21:51
 2015-07-17, 21:57 #38 storflyt32   Feb 2013 491 Posts http://factordb.com/index.php?id=1100000000792565896 If you are having the time.
2015-07-18, 15:34   #39
chris2be8

Sep 2009

1001011110012 Posts

Quote:
 Originally Posted by storflyt32 Hi, Jayder. If I happen to multiply a known RSA factor with a Fermat factor, I might end up at a number like this, 19036657588412969111505965532704495313206606970654378333477575250997660572 96146492268504477755829049148371391847449774943227537240957345732440163922533773 3449295565780737 It is a C170, by the way. Try factorizing this number. Based on the information given, it should not be an impossible thing to do.
Just trying Fermat numbers from 2^2+1 upwards in factordb I soon found 2^4096+1 has a common factor with it. I could have written a program to do it, but that would have taken longer than trying them by hand.

Chris

 2015-07-19, 12:02 #40 storflyt32   Feb 2013 491 Posts Thanks! Also while noticing the other one as well, I took the time of doing the same with the other P116 of RSA-232. But perhaps this was not a result of factorization skills or ability, but rather something else instead. Last fiddled with by storflyt32 on 2015-07-19 at 12:03
 2015-07-25, 10:50 #41 tha     Dec 2002 25·33 Posts Found a factor for exponent 12408313 through P-1. Two factors actually. The pc used E=12 for the factoring and came up with a B2 limit for regular P-1 just 10% under a billion. Nice found.
 2015-09-11, 02:08 #42 storflyt32   Feb 2013 491 Posts (4331*2^1255628+1) has factors 3, 3 and 7 (63) The remaining part is composite. pfgw64 -q"((4331*2^1255628+1)/63)" PFGW Version 3.7.7.64BIT.20130722.Win_Dev [GWNUM 27.11] ((4331*2^1255628+1)/63) is composite: RES64: [05A11D83AA626AEE] (1756.0910s+0.0013s) Last fiddled with by storflyt32 on 2015-09-11 at 02:33
 2015-09-11, 05:00 #43 storflyt32   Feb 2013 1111010112 Posts http://factordb.com/index.php?id=1100000000803014320 The initial C169 there. Added the P18 right now. The rest or remaining is still in the blue. Try "dividing" the C1133 of (2^4096+1) on this C169 and see what you get. I could add this factor as well. http://factordb.com/index.php?id=1100000000803014664 My best one in a little while. Last fiddled with by storflyt32 on 2015-09-11 at 05:38
 2015-09-12, 22:57 #44 storflyt32   Feb 2013 491 Posts C156 = 1046549594684669247529542854996104560606610105651308122647323036788396252 83702968161057585901197429244373750447622645448631676673651879291916651670550446 647 http://factordb.com/index.php?id=1100000000226834094 "Divide" this number from RSA-1024 above and and next factor it and you get a P152 back in return. http://factordb.com/index.php?id=1100000000803112399 Done already for orders sake. Last fiddled with by storflyt32 on 2015-09-12 at 23:01

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