Didn't even find a useless factor of an uninteresting number! Take that!

[VictordeHolland]

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?

[petrw1]

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

[Jayder]

Originally Posted by VictordeHolland

I hope you meant it ironically?

I hope so.

[storflyt32]

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.

[storflyt32]

http://factordb.com/index.php?id=1100000000792565896

If you are having the time.

[chris2be8]

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

[storflyt32]

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.

[tha]

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.

[storflyt32]

(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)

[storflyt32]

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.

[storflyt32]

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.