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 2017-09-17, 06:35 #1 crack11   Sep 2017 1816 Posts math gcd problem need help Dear all im new in this Greatest forum i have problem in mathematica i need calculate gcd from this string: Code: Z1:=(7580104959982914123117804044806461820154572036369549529405552162648856956231245030405896783337631871321017085933334306430501343909365379890910193903441-(7601611438277968963930435339966375537762723788929138241505092335032216337024111944145650540579951639515460945444623092013993572866002842083492323809287290^17592186175489)); Z2:= (7580104959982914123117804044806461820154572036369549301773204651044654156328611994019678602790933052049997074737942147009504600337458372628655015658163-(5472021051232020294637156058031796107019454396525172260491306567922450488302345750910648307191204110931670031994886144725045972546892458995859985546716414^17592186175489)); Z3:= (7580104959982914050609440727680305970398447676033232174897745114621599628756001756455762578505630805317234747401759098214730033873908508468766892578356-(2716401471494295676405217606243925186946305783849093640906079739928627393562677984831598246598185728284424287135181309232467496805930321500988187816347957^17592186175489)); ToUpperCase[IntegerString[(GCD[Z1,Z2,Z3]),16]] but math show error i attachment this error img please help me to solve this issu... Attached Thumbnails
 2017-09-18, 06:50 #2 ewmayer ∂2ω=0     Sep 2002 República de California 25·307 Posts Your problem is not 'in mathematica', your problem is that you are blindly attempting to get mathematica to do a computation without having thought through how large those exponentials you are inputting are. So tell us - and you don't need any fancy maths package for this, just some simple digit-counting and basic algebra - roughly how many decimal digits will your GCD inputs have once the exponentiations are done?
 2017-09-18, 11:00 #3 crack11   Sep 2017 23·3 Posts Dear sir, without mathe matica how its possibel its 64bit gcd computation my laptop dell i7 with 8GB RAM...
 2017-09-18, 11:34 #4 axn     Jun 2003 477610 Posts The problem is the size of the calculation. What you want to do is impossible
 2017-09-18, 11:37 #5 a1call     "Rashid Naimi" Oct 2015 Remote to Here/There 7×277 Posts Those numbers are too large for the available memory. Why don't you try the GCD function without the exponents and then raise it to the power of the smallest exponent? The GCD (8^a,6^b,18^c)= 2^( Smallest of a,b ,c) You can do all that programmatically if you wish.
 2017-09-18, 11:38 #6 crack11   Sep 2017 23·3 Posts i need 512 rsakey from this string please help me..
2017-09-18, 14:22   #7
VBCurtis

"Curtis"
Feb 2005
Riverside, CA

41·109 Posts

Quote:
You've been given help. You haven't answered any of the questions posed in the replies, nor shown any indication you comprehend what you're trying to do.

2017-09-18, 14:24   #8
VBCurtis

"Curtis"
Feb 2005
Riverside, CA

41·109 Posts

Quote:
 Originally Posted by a1call The GCD (8^a,6^b,18^c)= 2^( Smallest of a,b ,c)
Huh? If a = 1, b = 2, c = 2, I'm pretty sure the GCD is not 2^1.

2017-09-18, 15:22   #9
CRGreathouse

Aug 2006

2×2,969 Posts

Quote:
 Originally Posted by VBCurtis Huh? If a = 1, b = 2, c = 2, I'm pretty sure the GCD is not 2^1.
Right, it should have been min(3a, b, c). But the point remains that the gcd needs to be computed symbolically rather than by blindly expanding then taking the gcd.

 2017-09-18, 15:48 #10 Dr Sardonicus     Feb 2017 Nowhere 23·11·43 Posts Hmm. I'm not familiar with Mathematica syntax. The three integers all seem to be of the form a - b^17592186175489. The three values of a are 7580104959982914123117804044806461820154572036369549529405552162648856956231245030405896783337631871321017085933334306430501343909365379890910193903441 7580104959982914123117804044806461820154572036369549301773204651044654156328611994019678602790933052049997074737942147009504600337458372628655015658163 7580104959982914050609440727680305970398447676033232174897745114621599628756001756455762578505630805317234747401759098214730033873908508468766892578356 which have a suspiciously long block of MSD's in common. Beyond that, I don't see anything particularly useful.
2017-09-18, 16:26   #11
a1call

"Rashid Naimi"
Oct 2015
Remote to Here/There

7×277 Posts

Quote:
 Originally Posted by VBCurtis Huh? If a = 1, b = 2, c = 2, I'm pretty sure the GCD is not 2^1.
Good point. I did not think of that.
Thank you.

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