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#133 |
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Feb 2013
2×229 Posts |
http://factordb.com/index.php?id=1100000000820473763
http://factordb.com/index.php?id=1100000000820473569 The C289 in the first link has a P35 factor which was added a short while ago. P35 = 39329081168732850267866544033284131 By means of trial division here. But factoring the C289 in the first link really does make it official. This will probably take some time. The remaining number becomes a P255. Last fiddled with by storflyt32 on 2016-02-07 at 17:42 |
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#134 |
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Feb 2013
2·229 Posts |
If you happen to be reading some of the discussion taking place somewhere else here, the story becomes as follows:
2^31 - 1 = 2147483647 2^2147483647 - 1 = ... isprime(...) (?) What is next, or is there something else that could be tried out instead? Last fiddled with by storflyt32 on 2016-02-09 at 08:22 |
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#135 |
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Sep 2002
Database er0rr
3,739 Posts |
http://www.doublemersennes.org/mm31.php
![]() "Of these, MMp is known to be prime for p = 2, 3, 5, 7; for p = 13, 17, 19, and 31, explicit factors have been found showing that the corresponding double Mersenne numbers are not prime." from the home page. Last fiddled with by paulunderwood on 2016-02-09 at 09:05 |
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#136 |
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Feb 2013
2×229 Posts |
Thanks Paul.
Noted down that page for reference. |
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#137 |
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Feb 2013
2×229 Posts |
Always a difference between those idiots (not Paul) and any geniuses.
Remeber the chess robot being mentioned. Last fiddled with by storflyt32 on 2016-02-10 at 04:50 |
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#138 |
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Feb 2013
1CA16 Posts |
Paul, or someone else here, a question for you.
http://factordb.com/index.php?id=1100000000822420576 If you look at the P44 and P46 pair, one might get the impression that these factors became known as a result of the factorization of RSA-768 or the similar. Now, smaller factors are being added as well in an attempt to factorize even larger numbers of the same type for which there currently are no known factors for, because these numbers may be having only two factors. In the end you may actually be able to find these factors, but only because you are getting a lot of others which does not divide the number you are trying to find. Is this now the only way of doing this, or should we still believe that "brute force" is the better way of solving these problems? Last fiddled with by storflyt32 on 2016-02-12 at 10:20 |
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#139 | ||||
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"Curtis"
Feb 2005
Riverside, CA
4,861 Posts |
Quote:
Quote:
Quote:
Quote:
What is your "brute force" method to factor a number? To be specific: If I gave you a 512-bit RSA key, and told you I was sure it met the RSA style (exactly two factors, each the same bit length), how would you factor it? Please be more specific than "yafu factor(numberyougiveme)". |
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#140 |
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Feb 2013
45810 Posts |
I read the rest of it before posting.
http://factordb.com/index.php?id=1100000000822862072 Not with ecm and 2^21 curves here. By the way, I happen to be curious about the possible P306. How do you get this number? I will give it a try. http://factordb.com/index.php?id=1100000000823523157 Edit: Made a copy and paste error and found this P219. Last fiddled with by storflyt32 on 2016-02-15 at 09:07 |
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#141 |
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Feb 2013
2×229 Posts |
Could you please refer me to the mentioned a(196)?
http://mersenneforum.org/showpost.ph...&postcount=111 Not able to find it right now. Last fiddled with by storflyt32 on 2016-02-15 at 10:06 |
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#142 |
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Feb 2013
1CA16 Posts |
http://factordb.com/index.php?id=1100000000822862072
Thanks for doing that. Edit: http://factordb.com/index.php?id=1100000000823542817 http://factordb.com/index.php?id=1100000000823541641 What a coincidence. Still working on the C126. Last fiddled with by storflyt32 on 2016-02-15 at 12:23 |
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#143 |
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Feb 2013
2·229 Posts |
Another queston for you.
Definitely 2^31-1, 2^31+1, 2^127-1 or 2^127+1 are easy numbers to factorize. You have the same list of factors there, in progressively larger order, including Therefore a number like 438074125819448964817444191295445945307799572735 is easy to factorize as well. Slightly more diiffcult when adding 2 to this number. Surprisingly, 438074125819448964817444191295445945307799572737 had a P38 being added to the FDB. What if you rather say 2^6700417-1 or 2^6700417+1 instead? The latter number is having factor P1 = 3. In comparison, I have not checked a factor like P8 = 14231699 for such a thing. Is this P8 a Mersenne factor, or is it a Fermat factor? Anyway, was able to get these two results. pfgw64 -q"(2^6400417-1)" PFGW Version 3.7.7.64BIT.20130722.Win_Dev [GWNUM 27.11] (2^6400417-1) is composite: RES64: [D136471B5C1D058B] (42756.7714s+0.0024s) pfgw64 -q"((2^6400417+1)/3)" PFGW Version 3.7.7.64BIT.20130722.Win_Dev [GWNUM 27.11] ((2^6400417+1)/3) is composite: RES64: [E4558F8BD2593646] (39807.7262s+0.0811s) Last fiddled with by storflyt32 on 2016-02-15 at 14:13 |
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