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Diffstat (limited to 'doc/man3/EC_POINT_new.pod')
| -rw-r--r-- | doc/man3/EC_POINT_new.pod | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/doc/man3/EC_POINT_new.pod b/doc/man3/EC_POINT_new.pod index e2e2c129eb..fc8643cd60 100644 --- a/doc/man3/EC_POINT_new.pod +++ b/doc/man3/EC_POINT_new.pod @@ -124,9 +124,9 @@ public concept. A valid point on a curve is the special point at infinity. A point is set to be at infinity by calling EC_POINT_set_to_infinity(). -The affine co-ordinates for a point describe a point in terms of its x and y +The affine coordinates for a point describe a point in terms of its x and y position. The function EC_POINT_set_affine_coordinates() sets the B<x> and B<y> -co-ordinates for the point B<p> defined over the curve given in B<group>. The +coordinates for the point B<p> defined over the curve given in B<group>. The function EC_POINT_get_affine_coordinates() sets B<x> and B<y>, either of which may be NULL, to the corresponding coordinates of B<p>. @@ -140,27 +140,27 @@ EC_POINT_get_affine_coordinates_GF2m() are synonyms for EC_POINT_get_affine_coordinates(). They are defined for backwards compatibility only and should not be used. -As well as the affine co-ordinates, a point can alternatively be described in -terms of its Jacobian projective co-ordinates (for Fp curves only). Jacobian -projective co-ordinates are expressed as three values x, y and z. Working in -this co-ordinate system provides more efficient point multiplication -operations. A mapping exists between Jacobian projective co-ordinates and -affine co-ordinates. A Jacobian projective co-ordinate (x, y, z) can be written -as an affine co-ordinate as (x/(z^2), y/(z^3)). Conversion to Jacobian -projective from affine co-ordinates is simple. The co-ordinate (x, y) is mapped +As well as the affine coordinates, a point can alternatively be described in +terms of its Jacobian projective coordinates (for Fp curves only). Jacobian +projective coordinates are expressed as three values x, y and z. Working in +this coordinate system provides more efficient point multiplication +operations. A mapping exists between Jacobian projective coordinates and +affine coordinates. A Jacobian projective coordinate (x, y, z) can be written +as an affine coordinate as (x/(z^2), y/(z^3)). Conversion to Jacobian +projective from affine coordinates is simple. The coordinate (x, y) is mapped to (x, y, 1). Although deprecated in OpenSSL 3.0 and should no longer be used, -to set or get the projective co-ordinates in older versions use +to set or get the projective coordinates in older versions use EC_POINT_set_Jprojective_coordinates_GFp() and EC_POINT_get_Jprojective_coordinates_GFp() respectively. Modern versions should instead use EC_POINT_set_affine_coordinates() and EC_POINT_get_affine_coordinates(), performing the conversion manually using the above maps in such rare circumstances. -Points can also be described in terms of their compressed co-ordinates. For a +Points can also be described in terms of their compressed coordinates. For a point (x, y), for any given value for x such that the point is on the curve there will only ever be two possible values for y. Therefore, a point can be set using the EC_POINT_set_compressed_coordinates() function where B<x> is the x -co-ordinate and B<y_bit> is a value 0 or 1 to identify which of the two +coordinate and B<y_bit> is a value 0 or 1 to identify which of the two possible values for y should be used. The functions EC_POINT_set_compressed_coordinates_GFp() and |