@Override
  public List<RpslObject> authenticate(
      final PreparedUpdate update, final UpdateContext updateContext) {
    final RpslObject updatedObject = update.getUpdatedObject();
    final RpslAttribute typeAttribute = updatedObject.getTypeAttribute();
    final IpInterval addressPrefix = IpInterval.parse(typeAttribute.getCleanValue());

    final List<RpslObject> ipObjects = getIpObjects(addressPrefix);
    if (ipObjects.isEmpty()) {
      throw new AuthenticationFailedException(
          UpdateMessages.authenticationFailed(
              updatedObject, typeAttribute.getType(), Collections.<RpslObject>emptyList()),
          Collections.<RpslObject>emptyList());
    }

    final Set<RpslObject> allCandidates = Sets.newLinkedHashSet();
    final List<Message> authenticationMessages = Lists.newArrayList();

    for (final RpslObject ipObject : ipObjects) {
      if (ipObject.containsAttribute(AttributeType.MNT_ROUTES)) {
        final List<RpslObject> candidates =
            getCandidatesForMntRoutesAuthentication(ipObject, update);
        allCandidates.addAll(candidates);

        final List<RpslObject> authenticated =
            authenticationModule.authenticate(update, updateContext, candidates);
        if (authenticated.isEmpty()) {
          authenticationMessages.add(
              UpdateMessages.authenticationFailed(ipObject, AttributeType.MNT_ROUTES, candidates));
        } else {
          return authenticated;
        }
      }
    }

    if (!authenticationMessages.isEmpty()) {
      throw new AuthenticationFailedException(authenticationMessages, allCandidates);
    }

    for (final RpslObject ipObject : ipObjects) {
      final IpInterval ipInterval = IpInterval.parse(ipObject.getTypeAttribute().getCleanValue());
      if (!addressPrefix.equals(ipInterval)
          && ipObject.containsAttribute(AttributeType.MNT_LOWER)) {
        final List<RpslObject> candidates =
            objectDao.getByKeys(
                ObjectType.MNTNER, ipObject.getValuesForAttribute(AttributeType.MNT_LOWER));
        allCandidates.addAll(candidates);

        final List<RpslObject> authenticated =
            authenticationModule.authenticate(update, updateContext, candidates);
        if (authenticated.isEmpty()) {
          authenticationMessages.add(
              UpdateMessages.authenticationFailed(ipObject, AttributeType.MNT_LOWER, candidates));
        } else {
          return authenticated;
        }
      }
    }

    if (!authenticationMessages.isEmpty()) {
      throw new AuthenticationFailedException(authenticationMessages, allCandidates);
    }

    for (final RpslObject ipObject : ipObjects) {
      if (ipObject.containsAttribute(AttributeType.MNT_BY)) {
        final List<RpslObject> candidates =
            objectDao.getByKeys(
                ObjectType.MNTNER, ipObject.getValuesForAttribute(AttributeType.MNT_BY));
        allCandidates.addAll(candidates);

        final List<RpslObject> authenticated =
            authenticationModule.authenticate(update, updateContext, candidates);
        if (authenticated.isEmpty()) {
          authenticationMessages.add(
              UpdateMessages.authenticationFailed(ipObject, AttributeType.MNT_BY, candidates));
        } else {
          return authenticated;
        }
      }
    }

    if (!authenticationMessages.isEmpty()) {
      throw new AuthenticationFailedException(authenticationMessages, allCandidates);
    }

    throw new AuthenticationFailedException(
        UpdateMessages.authenticationFailed(
            updatedObject, typeAttribute.getType(), Collections.<RpslObject>emptyList()),
        allCandidates);
  }