deriveDkOvk method

Implementation

(OrchardDiversifierKey, OrchardOutgoingViewingKey) deriveDkOvk() {
  final k = rivk.toBytes();
  final b = [ak.toBytes(), nk.toBytes()];
  final r = PrfExpand.orchardDkOvk.apply(k, data: b);
  return (
    OrchardDiversifierKey(r.sublist(0, 32)),
    OrchardOutgoingViewingKey(r.sublist(32)),
  );
}