/* -*-c-*-
*
- * $Id: mpbarrett.h,v 1.1 1999/12/10 23:22:00 mdw Exp $
+ * $Id: mpbarrett.h,v 1.4 2004/04/01 12:50:09 mdw Exp $
*
* Barrett modular reduction
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mpbarrett.h,v $
+ * Revision 1.4 2004/04/01 12:50:09 mdw
+ * Add cyclic group abstraction, with test code. Separate off exponentation
+ * functions for better static linking. Fix a buttload of bugs on the way.
+ * Generally ensure that negative exponents do inversion correctly. Add
+ * table of standard prime-field subgroups. (Binary field subgroups are
+ * currently unimplemented but easy to add if anyone ever finds a good one.)
+ *
+ * Revision 1.3 2001/06/16 12:58:47 mdw
+ * Added simultaneous exponentiation with Barrett reduction.
+ *
+ * Revision 1.2 2000/10/08 12:03:44 mdw
+ * (mpbarrett_reduce): Cope with negative numbers.
+ *
* Revision 1.1 1999/12/10 23:22:00 mdw
* Barrett reduction support: works with even moduli.
*
* Returns: The residue of @m@ modulo the number in the reduction
* context.
*
- * Use: Performs an efficient modular reduction. The argument is
- * assumed to be positive.
+ * Use: Performs an efficient modular reduction.
*/
extern mp *mpbarrett_reduce(mpbarrett */*mb*/, mp */*d*/, mp */*m*/);
extern mp *mpbarrett_exp(mpbarrett */*mb*/, mp */*d*/, mp */*a*/, mp */*e*/);
+/* --- @mpbarrett_mexp@ --- *
+ *
+ * Arguments: @mpbarrett *mb@ = pointer to Barrett reduction context
+ * @mp *d@ = fake destination
+ * @const mp_expfactor *f@ = pointer to array of factors
+ * @size_t n@ = number of factors supplied
+ *
+ * Returns: If the bases are %$g_0, g_1, \ldots, g_{n-1}$% and the
+ * exponents are %$e_0, e_1, \ldots, e_{n-1}$% then the result
+ * is:
+ *
+ * %$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} \bmod m$%
+ */
+
+extern mp *mpbarrett_mexp(mpbarrett */*mb*/, mp */*d*/,
+ const mp_expfactor */*f*/, size_t /*n*/);
+
/*----- That's all, folks -------------------------------------------------*/
#ifdef __cplusplus