I ask this because I am study McEliece Cryptosystem. And to get the generator matrix of Goppa code I am using the right_kernel() instruction
Krnl = H.right_kernel(); but I get always these form. The parity check matrix is building using the matrix T, V and D. How I will be able to get generator matrix in other form? H: is a parity check matrix. T: Toepliz V: Vandermonde D: Diagonal 2013/4/18 William Stein <wst...@gmail.com> > On Thu, Apr 18, 2013 at 1:50 PM, Juan Grados <juan...@gmail.com> wrote: > > Dears members, > > > > I executed right_kernel() for any matrix H. Why always I get a basis > matrix > > in this form [I|A] (I:identity)? > > That's not true for the 1x2 matrix [1,0]: > > sage: matrix(1,2,[1,0]).right_kernel() > Free module of degree 2 and rank 1 over Integer Ring > Echelon basis matrix: > [0 1] > > The basis matrix is not of the form [I|A], for I the identity matrix. > > For a *random* matrix you'll get [I|A] though. > > William > > William > > > > > > > -- > > --------------------------------------------------------------------- > > MSc. Juan del Carmen Grados Vásquez > > Laboratório Nacional de Computação Científica > > Tel: +55 24 2233-6260 > > (http://www.lncc.br/) > > http://juaninf.blogspot.com > > --------------------------------------------------------------------- > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sage-support" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to sage-support+unsubscr...@googlegroups.com. > > To post to this group, send email to sage-support@googlegroups.com. > > Visit this group at http://groups.google.com/group/sage-support?hl=en. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > -- > William Stein > Professor of Mathematics > University of Washington > http://wstein.org > > -- > You received this message because you are subscribed to the Google Groups > "sage-support" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-support+unsubscr...@googlegroups.com. > To post to this group, send email to sage-support@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-support?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- --------------------------------------------------------------------- MSc. Juan del Carmen Grados Vásquez Laboratório Nacional de Computação Científica Tel: +55 24 2233-6260 (http://www.lncc.br/) http://juaninf.blogspot.com --------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
