It is calling __mul__ which is just above the __rmul__ portion of the code. According to documentation of __rmul__ ( http://docs.python.org/3.3/reference/datamodel.html#object.__rmul__) it just calls the implementation of __mul__ ( https://github.com/warner/python-ecdsa/blob/master/ecdsa/ellipticcurve.py#L109-138 )
HTH, Vijay. On Thu, Jan 30, 2014 at 12:32 PM, Raul Miller <rauldmil...@gmail.com> wrote: > I have been looking at this, and I did a straightforward conversion of > the python code to J (not quite complete). And I have a couple issues > I would like to talk through before proceeding (I've also not yet > studied Cliff Reiter's code). > > First, I would like to quibble with what I assume is the underlying > standards document. The value INFINITY behaves like a zero in the > context of addition. That strikes me as a bit odd. > > Second, though, I would like to understand python's rules a bit better > - what happens when one multiples a Point with integer? > > Specifically, consider this excerpt from > https://github.com/warner/python-ecdsa/blob/master/ecdsa/ellipticcurve.py > : > > p192 = Point( c192, Gx, Gy, r ) > > # Checking against some sample computations presented > # in X9.62: > > d = 651056770906015076056810763456358567190100156695615665659 > Q = d * p192 > > The definitions of p192 and d are trivial for me to translate: > > p192=. (c192;Gx;Gy;r) conew 'Point' > > d=. 651056770906015076056810763456358567190100156695615665659x > > But how do I translate Q? > > In the definition of Point, I saw the following bit of python: > > def __rmul__( self, other ): > """Multiply a point by an integer.""" > > return self * other > > But if that is the relevant code, all it is telling me is that > multiplication is defined in terms of multiplication - as far as I can > see, there is no other definition for multiplying a Point and an > integer, nor have I seen any constructor for constructing a Point from > an integer. > > Before I spend too much time chasing down rabbit holes (I really > should be working on some other issues), can someone explain to me > what is supposed to happen here? > > Thanks, > > -- > Raul > > On Wed, Jan 29, 2014 at 11:35 AM, Pascal Jasmin <godspiral2...@yahoo.ca> > wrote: > > > > > > With all of the mathematicians on this list, these functions have likely > been implemented before in J. > > > > elyptic curve point add, multiplication and double > > a python reference implementation: > https://github.com/warner/python-ecdsa/blob/master/ecdsa/ellipticcurve.py > > > > the functions are: __add__ __mul__ and double > > > > if I may suggest J explicit signatures for the first 2 functions as: > > > > F =: 4 : 0 > > 'yx yy yo' =. y > > 'xx xy xo' =. x > > ) > > > > Some other methods than the python reference could be considered here: > > > > http://en.wikipedia.org/wiki/Elliptic_curve_point_multiplication > > > > > > also appreciated if you have in implementation of inverse_mod > > for reference function of same nate at: > https://github.com/warner/python-ecdsa/blob/master/ecdsa/numbertheory.py > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
