diff --git a/censustree.go b/censustree.go
index c27d0d6..a83a155 100644
--- a/censustree.go
+++ b/censustree.go
@@ -136,8 +136,8 @@ func (t *Tree) Add(index, value []byte) error {
 	if t.snapshotRoot != nil {
 		return fmt.Errorf("cannot add to a snapshot trie")
 	}
-	if len(index) < 4 {
-		return fmt.Errorf("index too small (%d), minimum size is 4 bytes", len(index))
+	if len(index) < 4 || len(index) > MaxKeySize {
+		return fmt.Errorf("wrong key size: %d", len(index))
 	}
 	if len(value) > MaxValueSize {
 		return fmt.Errorf("index or value claim data too big")
@@ -162,11 +162,9 @@ func (t *Tree) AddBatch(indexes, values [][]byte) ([]int, error) {
 	if len(values) > 0 && len(indexes) != len(values) {
 		return wrongIndexes, fmt.Errorf("indexes and values have different size")
 	}
-	var hashedIndexes [][]byte
-	var hashedValues [][]byte
 	var value []byte
 	for i, key := range indexes {
-		if len(key) < 4 {
+		if len(key) < 4 || len(key) > MaxKeySize {
 			wrongIndexes = append(wrongIndexes, i)
 			continue
 		}
@@ -178,12 +176,10 @@ func (t *Tree) AddBatch(indexes, values [][]byte) ([]int, error) {
 			}
 			value = values[i]
 		}
-		hashedIndexes = append(hashedIndexes, asmt.Hasher(key))
-		hashedValues = append(hashedValues, asmt.Hasher(value))
-	}
-	_, err := t.Tree.Update(hashedIndexes, hashedValues)
-	if err != nil {
-		return wrongIndexes, err
+		_, err := t.Tree.Update([][]byte{asmt.Hasher(key)}, [][]byte{asmt.Hasher(value)})
+		if err != nil {
+			return wrongIndexes, err
+		}
 	}
 	atomic.StoreUint64(&t.size, 0) // TBD: improve this
 	return wrongIndexes, t.Commit()
@@ -205,28 +201,27 @@ func (t *Tree) GenProof(index, value []byte) ([]byte, error) {
 	t.updateAccessTime()
 	var err error
 	var ap [][]byte
-	var pvalue []byte
-	var bitmap []byte
+	var pvalue, bitmap []byte
 	var length int
+	var included bool
+	key := asmt.Hasher(index)
 	if t.snapshotRoot != nil {
-		bitmap, ap, length, _, _, pvalue, err = t.Tree.MerkleProofCompressedR(
-			asmt.Hasher(index),
+		bitmap, ap, length, included, _, pvalue, err = t.Tree.MerkleProofCompressedR(key,
 			t.snapshotRoot)
 		if err != nil {
 			return nil, err
 		}
 	} else {
-		bitmap, ap, length, _, _, pvalue, err = t.Tree.MerkleProofCompressed(
-			asmt.Hasher(index))
+		bitmap, ap, length, included, _, pvalue, err = t.Tree.MerkleProofCompressed(key)
 		if err != nil {
 			return nil, err
 		}
 	}
-	//if !included {
-	//	return nil, fmt.Errorf("not included")
-	//}
+	if !included {
+		return nil, nil
+	}
 	if !bytes.Equal(pvalue, asmt.Hasher(value)) {
-		return nil, fmt.Errorf("incorrect value on genProof")
+		return nil, fmt.Errorf("incorrect value or key on genProof")
 	}
 	return bare.Marshal(&Proof{Bitmap: bitmap, Length: length, Siblings: ap, Value: pvalue})
 }
diff --git a/censustree_test.go b/censustree_test.go
index 0746f79..b09bea4 100644
--- a/censustree_test.go
+++ b/censustree_test.go
@@ -2,8 +2,10 @@ package asmtree
 
 import (
 	"bytes"
+	"crypto/rand"
 	"fmt"
 	"testing"
+	"time"
 )
 
 func TestTree(t *testing.T) {
@@ -86,5 +88,186 @@ func TestTree(t *testing.T) {
 	if !valid {
 		t.Errorf("proof is invalid on tree2")
 	}
+}
+
+func TestProofs(t *testing.T) {
+	censusSize := 10000
+	storage := t.TempDir()
+	tr1 := &Tree{}
+	err := tr1.Init("test1", storage)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var keys, values [][]byte
+	for i := 0; i < censusSize; i++ {
+		keys = append(keys, RandomBytes(32))
+		values = append(values, RandomBytes(32))
+	}
+
+	i := 0
+	for i < censusSize-200 {
+		if fail, err := tr1.AddBatch(keys[i:i+200], values[i:i+200]); err != nil {
+			t.Fatal(err)
+		} else if len(fail) > 0 {
+			t.Fatalf("some keys failed to add on addBatch: %v", fail)
+		}
+		i += 200
+	}
+	// Add remaining claims (if size%200 != 0)
+	if i < censusSize {
+		if fail, err := tr1.AddBatch(keys[i:], values[i:]); err != nil {
+			t.Fatal(err)
+		} else if len(fail) > 0 {
+			t.Fatalf("some keys failed to add on addBatch: %v", fail)
+		}
+	}
+
+	root1 := tr1.Root()
+	data, err := tr1.Dump(root1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("dumped data size is: %d bytes", len(data))
+
+	// Get the size
+	s, err := tr1.Size(nil)
+	if err != nil {
+		t.Errorf("cannot get te size: %v", err)
+	}
+	if s != int64(censusSize) {
+		t.Errorf("size is wrong (have %d, expexted %d)", s, censusSize)
+	}
+
+	// Generate a proofs
+	time.Sleep(5 * time.Second)
+	proofs := [][]byte{}
+	for i := 0; i < censusSize; i++ {
+		p, err := tr1.GenProof(keys[i], values[i])
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(p) == 0 {
+			t.Fatal("proof not generated")
+		}
+		proofs = append(proofs, p)
+	}
+
+	// Check proofs
+	for i := 0; i < censusSize; i++ {
+		valid, err := tr1.CheckProof(keys[i], values[i], root1, proofs[i])
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !valid {
+			t.Errorf("proof %d is invalid", i)
+		}
+	}
 
 }
+
+// go test -v -run=- -bench=Tree -benchtime=30s .
+func BenchmarkTree(b *testing.B) {
+	b.ReportAllocs()
+
+	b.ResetTimer()
+	b.RunParallel(func(pb *testing.PB) {
+		// Create websocket client
+		for pb.Next() {
+			benchProofs(b, 100000)
+		}
+	})
+}
+
+func benchProofs(b *testing.B, censusSize int) {
+	totalTimer := time.Now()
+	storage := b.TempDir()
+	tr1 := &Tree{}
+	err := tr1.Init("test1", storage)
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	var keys, values [][]byte
+	for i := 0; i < censusSize; i++ {
+		keys = append(keys, RandomBytes(32))
+		values = append(values, RandomBytes(32))
+	}
+
+	timer := time.Now()
+	i := 0
+	for i < censusSize-200 {
+		if fail, err := tr1.AddBatch(keys[i:i+200], values[i:i+200]); err != nil {
+			b.Fatal(err)
+		} else if len(fail) > 0 {
+			b.Fatalf("some keys failed to add on addBatch: %v", fail)
+		}
+		i += 200
+	}
+	// Add remaining claims (if size%200 != 0)
+	if i < censusSize {
+		if fail, err := tr1.AddBatch(keys[i:], values[i:]); err != nil {
+			b.Fatal(err)
+		} else if len(fail) > 0 {
+			b.Fatalf("some keys failed to add on addBatch: %v", fail)
+		}
+	}
+	b.Logf("addBatch took %d ms", time.Since(timer).Milliseconds())
+
+	timer = time.Now()
+	root1 := tr1.Root()
+	data, err := tr1.Dump(root1)
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.Logf("dumped data size is: %d bytes", len(data))
+	b.Logf("dump took %d ms", time.Since(timer).Milliseconds())
+
+	// Get the size
+	s, err := tr1.Size(nil)
+	if err != nil {
+		b.Errorf("cannot get te size: %v", err)
+	}
+	if s != int64(censusSize) {
+		b.Errorf("size is wrong (have %d, expexted %d)", s, censusSize)
+	}
+
+	// Generate a proofs
+	timer = time.Now()
+	time.Sleep(5 * time.Second)
+	proofs := [][]byte{}
+	for i := 0; i < censusSize; i++ {
+		p, err := tr1.GenProof(keys[i], values[i])
+		if err != nil {
+			b.Fatal(err)
+		}
+		if len(p) == 0 {
+			b.Fatal("proof not generated")
+		}
+		proofs = append(proofs, p)
+	}
+	b.Logf("gen proofs took %d ms", time.Since(timer).Milliseconds())
+
+	// Check proofs
+	timer = time.Now()
+	for i := 0; i < censusSize; i++ {
+		valid, err := tr1.CheckProof(keys[i], values[i], root1, proofs[i])
+		if err != nil {
+			b.Fatal(err)
+		}
+		if !valid {
+			b.Errorf("proof %d is invalid", i)
+		}
+	}
+	b.Logf("check proofs took %d ms", time.Since(timer).Milliseconds())
+	b.Logf("[finished] %d ms", time.Since(totalTimer).Milliseconds())
+}
+
+func RandomBytes(n int) []byte {
+	b := make([]byte, n)
+	_, err := rand.Read(b)
+	if err != nil {
+		panic(err)
+	}
+	return b
+}