Hello, I am trying to solve the following equation for y in SAGE:
x*y = 1 (mod z^8+z^4+z^3+z+1) where x = x0+x1*z^1+x2*z^2+x3*z^3+x4*z^4+x5*z^5+x6*z^6+x7*z^7 y = ? x0,...,x7 are elements of GF(2). I do not know their values. I am searching for y in parametric form i.e. as a polynomial of z of degree 7 with coefficients - some functions of x0,...,x7. I define in SAGE: P.<x0,x1,x2,x3,x4,x5,x6,x7> = BooleanPolynomialRing(8, order='lex') Z.<z> = PolynomialRing(P) I try to do the following in SAGE y = inverse_mod(x0+x1*z^1+x2*z^2+x3*z^3+x4*z^4+x5*z^5+x6*z^6+x7*z^7, z^8+z^4+z^3+z+1) but it does not work. Alternatively, I try to define a ring of univariate polynomials of z with coeffients in P, every element of which is reduced (mod z^8+z^4+z^3+z+1), but I am not able to get the right syntax to do this in SAGE. Any help is appreciated. Thanks! --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
