diff --git a/src/arachne.c b/src/arachne.c
index f8b3508..8fc058a 100644
--- a/src/arachne.c
+++ b/src/arachne.c
@@ -1427,7 +1427,7 @@ dotSemiState ()
   // Open graph
   attack_number++;
   eprintf ("digraph semiState%i {\n", attack_number);
-  eprintf ("\tlabel = \"Protocol ");
+  eprintf ("\tlabel = \"[Id %i] Protocol ", sys->attackid);
   p = (Protocol) sys->current_claim->protocol;
   termPrint (p->nameterm);
   eprintf (", role ");
@@ -3066,9 +3066,13 @@ add_claim_specifics (const Claimlist cl, const Roledef rd)
 }
 
 //! Count a false claim
+/**
+ * Counts global attacks as well as claim instances.
+ */
 void
 count_false ()
 {
+  sys->attackid++;
   sys->current_claim->failed = statesIncrease (sys->current_claim->failed);
 }
 
diff --git a/src/modelchecker.c b/src/modelchecker.c
index a467393..5c21d58 100644
--- a/src/modelchecker.c
+++ b/src/modelchecker.c
@@ -1239,6 +1239,7 @@ violateClaim (const System sys, int length, int claimev, Termlist reqt)
   flag = 1;
 
   /* Count the violations */
+  sys->attackid++;
   sys->failed = statesIncrease (sys->failed);
   clinfo = sys->traceEvent[claimev]->claiminfo;
   clinfo->failed = statesIncrease (clinfo->failed);	// note: for modelchecking secrecy, this can lead to more fails (at further events in branches of the tree) than claim encounters
diff --git a/src/system.c b/src/system.c
index 3b21451..40f8c7e 100644
--- a/src/system.c
+++ b/src/system.c
@@ -104,6 +104,7 @@ systemInit ()
   sys->claimlist = NULL;
   sys->labellist = NULL;
   sys->match = 0;		// default matching
+  sys->attackid = 0;		// First attack will have id 1, because the counter is increased before any attacks are displayed.
 
   /* matching CLP */
   sys->constraints = NULL;	// no initial constraints
diff --git a/src/system.h b/src/system.h
index 91552e6..ea01969 100644
--- a/src/system.h
+++ b/src/system.h
@@ -163,6 +163,7 @@ struct system
   states_t interval;		//!< Used to update state printing at certain intervals
   states_t claims;		//!< Number of claims encountered.
   states_t failed;		//!< Number of claims failed.
+  int attackid;			//!< Global counter of attacks (used for assigning identifiers) within this Scyther call.
   int countScenario;		//!< Number of scenarios skipped.
 
   /* matching */
diff --git a/src/xmlout.c b/src/xmlout.c
index fbecbae..87fee45 100644
--- a/src/xmlout.c
+++ b/src/xmlout.c
@@ -752,6 +752,8 @@ xmlOutSemitrace (const System sys)
   printf ("<attack");
   /* add trace length attribute */
   printf (" tracelength=\"%i\"", get_semitrace_length ());
+  /* add attack id attribute (within this scyther call) */
+  printf (" id=\"%i\"", sys->attackid);
   printf (">\n");
   xmlindent++;