ZIP 215: use terminology consistent with the protocol spec for the Ed25519 curve.

("The Edwards form of Curve25519" is not a unique description; there are multiple
twisted Edwards curves birationally equivalent to Curve25519, but only one is
called Ed25519.)

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

zip-0215.html

@@ -37,7 +37,7 @@ License: BSD-2-Clause</pre>
                     <span class="math">\(A\)</span>
                  and
                     <span class="math">\(R\)</span>
-                 respectively on the Edwards form of Curve25519;</li>
+                 respectively on the complete twisted Edwards curve Ed25519;</li>
                 <li>
                     <span class="math">\(\underline{S}\)</span>
                  MUST represent an integer

zip-0215.rst

@@ -57,7 +57,7 @@ After activation of this ZIP, the :math:`\mathsf{JoinSplitSig}` validation rules
 in §5.4.5 of the protocol specification [#protocol]_ are changed to the following:
 
 - :math:`\underline{A}` and :math:`\underline{R}` MUST be encodings of points
-  :math:`A` and :math:`R` respectively on the Edwards form of Curve25519;
+  :math:`A` and :math:`R` respectively on the complete twisted Edwards curve Ed25519;
 - :math:`\underline{S}` MUST represent an integer :math:`S` less than :math:`\ell`;
 - The group equation :math:`[8][S]B = [8]R + [8][k]A` MUST be satisfied, where
   :math:`k` and :math:`B` are defined as in RFC 8032 sections §5.1.7 and §5.1