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#76 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-21 00:34:59

As the problem was set the a0,a1 a2 where knowns as the x3 y3 all the otheres wew unknowns.Alll the variables should be Gf(17) elements.

#77 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-21 00:26:28

Yes!if the system is sovlable the intersection points will be defined and there will be x0,y0...x2y2={0,...,16}. Remember that the operations are not the same as on real...

#78 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-21 00:15:14

Hmmm ok. I used an extension field GF 2^128 I used a polynomial basis representation and a pentanomial irreducible polynomial for the generation of the field/. But I think that if the system can be solved on GF(p) will be solved  at GF(2^128) .
So we can assume p=17.Why not?

#79 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-21 00:02:28

p is a prime number. The GF is constituted by the elements 0,1...p-1.

#80 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-20 22:43:27

All the variables known and unknown will be elements of a Galois Field. Multiplication Division, addition(=substraction) will be defined over the GF. The result of the operations will be GFs too. They are not integers but elements of the GF. I mean that alla the problem will be defined and solved over the GF.

#83 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-20 19:31:07

If we try a different approach and instead replacing the

to the formula we write

then the formula will be  e.g for 3 degree polynomials

So If again we know

we need a ste of 2x3=6 such polynomials to solve the system and the system remains linear i.e. to get the
afterwards that we have defined

we can solve


and recover the missing intersection points.

So it seems that it can be solved over GF. I think...

#84 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-19 23:51:36

Whats this?I ve never heard it. Can this solve the aforementioned problem?

You give me hope!

#85 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-19 23:39:53

I think that when the set of equations is constituted by polynomials of degree-n, an unknown

will come up.

I dont know how

can be computed over GFs.

#86 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-19 21:52:46

No..It is not easy to test it. I have written in C a galois field multiplier and divider for an irreducilbe polynomial of degree 128.

The addition is simply an xor.

The equations are the same that I was posted in previous posts.

I google it and the results that wre obtained confused me. e.g. I tried to read the following thesis but with no result.

If i undersstood correctly the problem is not easily solvable but I am not sure that this thesis copes the same problem as mine


https://openaccess.leidenuniv.nl/bitstream/handle/1887/4392/Thesis.pdf?sequence=1

#87 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-19 19:44:52

Yes I meant a Finite feild generated by a prime n or an irreducible polynomial.

I am not sure that is solvable if the equations of the set are nonlinear i.e. te polynomials are of 2-degree 3- etc...

#88 Help Me ! » Solve a set of Equations over Galois Field » 2013-07-19 11:40:08

Herc11
Replies: 0

I have the following set of equations:


are known and they are chosen from a
. I want to find 

Does the previous set of equations is solvable?

And more...

If I have the following set of equations:



where 

are the unknown GF elements.
Note:the equations of the second set are not linear.

Is that set of equations solvable over the GF?

#89 Re: Help Me ! » Define the intersection points of polynomials » 2013-07-19 11:33:10

Hey bobby m,
Do you know if the set of equations that were talking about can be solved over Galois Fields?Or where to search?

#90 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-22 20:03:03

To be honest, I want to know if by having 2n equations

(of the previous form==leading coef.+ 1 point of the polynomial)

I can define the intersection point of the n degree polynomials.

You and  anomnimistefy prove that for the case of n=2, n=3 the previous case stands.

I think it stands for every n.

#91 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-22 05:13:29

No, only I want to see...just being curious!

#93 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-21 20:16:22

I am familiar with Galois Fields and the operations executed over GFs but it is not ot easy to explain...

#94 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-21 20:00:09

Something like that...

The problem is that when you work over Finite fields,

addition multiplication and division are not equal to standard operations. operations are executed modulo the prime number etc..etc..

#95 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-21 19:52:49

Ok, if the operations were over a galois field will have  any difference?

#97 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-21 19:27:18

Thats nice!
So I think one can say that If you have n intesection points, and someone provides you with the lead coeficient and a point of 2n polynomials you can define the intersection point.
Scool student?

#98 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-21 17:28:09

Hi anonimnystefy,

See the posts #133,135 and 146,147.

The aim is to solve a set of 6 equations of a_3 with the information provided in post 133 and 135.

I thinh that you can with mathematica.

You have 6 equations, with 6 unknown variables. I cant see why this is not sovlable.

#99 Re: Help Me ! » Define the intersection points of polynomials » 2013-06-21 09:31:24

By the way are you students or college students?

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