# toWeierstrass -- A method to transform a smooth plane cubic into Weierstrass form.

## Synopsis

• Usage:
toWeierstrass(List,List,Thing)
• Inputs:
• L, the coefficients of a plane cubic.
• O, the coordinates of a point over the curve.
• K, any field
• Outputs:

## Description

The method use the a modified version Nagell's algorithm which works in any characteristic.

Reference: Tibouchi, M. ''A Nagell Algorithm in Any Characteristic'', Cryptography and Security: From Theory to Applications, 474--479, 2012.

 i1 : toWeierstrass({-1,0,+1,0,0,+1,0,-1,0,+2},{1,2,1},ZZ/13) The point is not on the curve

## Ways to use toWeierstrass :

• "toWeierstrass(List,List,Thing)"

## For the programmer

The object toWeierstrass is .