/* Read x bit and then reset it */
negative = bignum_bit(point->y, point->curve->fieldBits - 1);
bignum_set_bit(point->y, point->curve->fieldBits - 1, 0);
/* Read x bit and then reset it */
negative = bignum_bit(point->y, point->curve->fieldBits - 1);
bignum_set_bit(point->y, point->curve->fieldBits - 1, 0);