Rationalise the sliding-window threshold. Drop guarantee that right

[u/mdw/catacomb] / ec.h

diff --git a/ec.h b/ec.h
index 07f1468..680bf9c 100644 (file)
--- a/ec.h
+++ b/ec.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: ec.h,v 1.5 2004/03/21 22:52:06 mdw Exp $
+ * $Id: ec.h,v 1.6 2004/03/22 02:19:10 mdw Exp $
  *
  * Elliptic curve definitions
  *
@@ -30,6 +30,11 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: ec.h,v $
+ * Revision 1.6  2004/03/22 02:19:10  mdw
+ * Rationalise the sliding-window threshold.  Drop guarantee that right
+ * arguments to EC @add@ are canonical, and fix up projective implementations
+ * to cope.
+ *
  * Revision 1.5  2004/03/21 22:52:06  mdw
  * Merge and close elliptic curve branch.
  *
@@ -95,9 +100,12 @@ typedef struct ec_mulfactor {
 /* --- Elliptic curve operations --- *
  *
  * All operations (apart from @destroy@ and @in@) are guaranteed to be
- * performed on internal representations of points.  Moreover, the second
- * argument to @add@ and @mul@ is guaranteed to be the output of @in@ or
- * @fix@.
+ * performed on internal representations of points.
+ *
+ * (Historical note.  We used to guarantee that the second to @add@ and @mul@
+ * was the output of @in@ or @fix@, but this canonification turned out to
+ * make the precomputation in @ec_exp@ too slow.  Projective implementations
+ * must therefore cope with a pair of arbitrary points.)
  */
 
 typedef struct ec_ops {