diff --git a/brandt.c b/brandt.c
index 6c334b8..b175c3e 100644
--- a/brandt.c
+++ b/brandt.c
@@ -49,6 +49,41 @@ BRANDT_init (struct GNUNET_CRYPTO_EccDlogContext *dlogctx)
 }
 
 
+static void
+advance_round (struct BRANDT_Auction *auction, enum auction_type atype, enum outcome_type outcome)
+{
+	unsigned char *buf;
+	size_t buflen;
+
+	/* if we got the current round message from all participants, advance to
+	 * next round */
+	for (uint16_t i = 0; i < auction->n; i++)
+		if (!gcry_mpi_test_bit (auction->round_progress, i))
+			return;
+
+	gcry_mpi_clear_highbit (auction->round_progress, 0);
+	if (msg_last == ++(auction->cur_round))
+	{
+	}
+
+	if (!handler_out[atype][outcome][auction->cur_round] ||
+	    !(buf = handler_out[atype][outcome][auction->cur_round](auction, &buflen)))
+	{
+		/** \todo */
+		weprintf ("wow fail out");
+		return;
+	}
+
+	/** \todo: add msgtype header in the handler_out functions */
+
+	/* last message only sent to seller, others are broadcasted */
+	if (msg_decrypt == auction->cur_round)
+		auction->ucast (auction->closure, buf, buflen);
+	else
+		auction->bcast (auction->closure, buf, buflen);
+}
+
+
 void
 BRANDT_got_message (struct BRANDT_Auction *auction,
                     uint16_t              sender,
@@ -56,8 +91,8 @@ BRANDT_got_message (struct BRANDT_Auction *auction,
                     size_t                msg_len)
 {
 	uint16_t    mtype = *(uint16_t *)msg;
-	int         atype;
-	int         outcome;
+	enum auction_type         atype;
+	enum outcome_type         outcome;
 	enum rounds round = auction->cur_round;
 
 	atype = auction->desc->m > 0 ? auction_mPlusFirstPrice : auction_firstPrice;
@@ -65,6 +100,13 @@ BRANDT_got_message (struct BRANDT_Auction *auction,
 
 	/** \todo: cache out of order messages */
 
+	/* check if we already got that round message from the same user */
+	if (gcry_mpi_test_bit (auction->round_progress, sender))
+	{
+		weprintf ("got a duplicate message from user %d", sender);
+		return;
+	}
+
 	if (!handler_in[atype][outcome][round] ||
 	    !handler_in[atype][outcome][round](auction,
 	                                       msg + sizeof (mtype),
@@ -72,6 +114,10 @@ BRANDT_got_message (struct BRANDT_Auction *auction,
 	                                       sender))
 	{
 		/** \todo */
-		weprintf ("wow fail");
+		weprintf ("wow fail in");
+		return;
 	}
+	gcry_mpi_set_bit (auction->round_progress, sender);
+
+	advance_round (auction, atype, outcome);
 }
diff --git a/brandt.h b/brandt.h
index fe50896..ec3c959 100644
--- a/brandt.h
+++ b/brandt.h
@@ -170,6 +170,10 @@ BRANDT_free ();
 /**
  * Receive a message related to a specific auction.
  *
+ * If the message is from a future round and cannot be processed yet, it is
+ * cached in RAM. It will not be stored on disc until it can be used, since the
+ * messages completing the previous round should all arrive relatively soon.
+ *
  * @param[in] auction The pointer returned by BRANDT_join() or BRANDT_new() from
  * which message @a msg was received.
  * @param[in] sender The id of the sender.
diff --git a/internals.h b/internals.h
index 656e798..ce67934 100644
--- a/internals.h
+++ b/internals.h
@@ -79,6 +79,8 @@ struct BRANDT_DescrP {
 struct BRANDT_Auction {
 	struct BRANDT_DescrP *desc; /** pointer to the auction information */
 
+	void *closure;              /** auction closure given by the user */
+
 	BRANDT_CbBroadcast bcast;   /** broadcast callback */
 	BRANDT_CbUnicast   ucast;   /** unicast callback */
 	BRANDT_CbResult    result;  /** result reporting callback */