diff --git a/pkg/detection/bench_test.go b/pkg/detection/bench_test.go
new file mode 100644
index 0000000..0d49d0d
--- /dev/null
+++ b/pkg/detection/bench_test.go
@@ -0,0 +1,31 @@
+package detection
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/BlackVectorOps/semantic_firewall/v3/pkg/analysis/topology"
+)
+
+func BenchmarkGenerateTopologyHash(b *testing.B) {
+	topo := &topology.FunctionTopology{
+		ParamCount:     2,
+		ReturnCount:    1,
+		BlockCount:     10,
+		InstrCount:     50,
+		LoopCount:      2,
+		BranchCount:    3,
+		CallSignatures: make(map[string]int),
+	}
+
+	// Populate with some call signatures
+	for i := 0; i < 100; i++ {
+		key := fmt.Sprintf("pkg.Func%d", i)
+		topo.CallSignatures[key] = i % 5
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		GenerateTopologyHash(topo)
+	}
+}
diff --git a/pkg/detection/engine.go b/pkg/detection/engine.go
index c8b2369..9d13564 100644
--- a/pkg/detection/engine.go
+++ b/pkg/detection/engine.go
@@ -203,15 +203,16 @@ func GenerateTopologyHash(topo *topology.FunctionTopology) string {
 	builder.WriteString("BR")
 	builder.WriteString(strconv.Itoa(topo.BranchCount))
 
-	var calls []string
+	calls := make([]string, 0, len(topo.CallSignatures))
+	buf := make([]byte, 0, 128)
 	for call, count := range topo.CallSignatures {
-		var cb strings.Builder
-		cb.WriteString(strconv.Itoa(len(call)))
-		cb.WriteString(":")
-		cb.WriteString(call)
-		cb.WriteString(":")
-		cb.WriteString(strconv.Itoa(count))
-		calls = append(calls, cb.String())
+		buf = buf[:0]
+		buf = strconv.AppendInt(buf, int64(len(call)), 10)
+		buf = append(buf, ':')
+		buf = append(buf, call...)
+		buf = append(buf, ':')
+		buf = strconv.AppendInt(buf, int64(count), 10)
+		calls = append(calls, string(buf))
 	}
 	sort.Strings(calls)
 	builder.WriteString(strings.Join(calls, ";"))