diff --git a/core/src/main/java/ch/dissem/bitmessage/entity/ObjectMessage.java b/core/src/main/java/ch/dissem/bitmessage/entity/ObjectMessage.java
index fee761c..8e386f7 100644
--- a/core/src/main/java/ch/dissem/bitmessage/entity/ObjectMessage.java
+++ b/core/src/main/java/ch/dissem/bitmessage/entity/ObjectMessage.java
@@ -96,7 +96,7 @@ public class ObjectMessage implements MessagePayload {
     }
 
     public InventoryVector getInventoryVector() {
-        return new InventoryVector(
+        return InventoryVector.fromHash(
                 Bytes.truncate(cryptography().doubleSha512(nonce, getPayloadBytesWithoutNonce()), 32)
         );
     }
diff --git a/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/InventoryVector.java b/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/InventoryVector.java
index 9a3b258..e1f8f60 100644
--- a/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/InventoryVector.java
+++ b/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/InventoryVector.java
@@ -52,10 +52,19 @@ public class InventoryVector implements Streamable, Serializable {
         return hash;
     }
 
-    public InventoryVector(byte[] hash) {
+    private InventoryVector(byte[] hash) {
+        if (hash == null) throw new IllegalArgumentException("hash must not be null");
         this.hash = hash;
     }
 
+    public static InventoryVector fromHash(byte[] hash) {
+        if (hash == null) {
+            return null;
+        } else {
+            return new InventoryVector(hash);
+        }
+    }
+
     @Override
     public void write(OutputStream out) throws IOException {
         out.write(hash);
diff --git a/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Message.java b/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Message.java
index 5bba98b..aea4368 100644
--- a/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Message.java
+++ b/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Message.java
@@ -184,7 +184,7 @@ public class Message implements ExtendedEncoding.ExtendedType {
             MPArray<MPBinary> parents = (MPArray<MPBinary>) map.get(mp("parents"));
             if (parents != null) {
                 for (MPBinary parent : parents) {
-                    builder.addParent(new InventoryVector(parent.getValue()));
+                    builder.addParent(InventoryVector.fromHash(parent.getValue()));
                 }
             }
             @SuppressWarnings("unchecked")
diff --git a/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Vote.java b/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Vote.java
index 6ea174f..1c13440 100644
--- a/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Vote.java
+++ b/core/src/main/java/ch/dissem/bitmessage/entity/valueobject/extended/Vote.java
@@ -105,7 +105,7 @@ public class Vote implements ExtendedEncoding.ExtendedType {
             Vote.Builder builder = new Vote.Builder();
             MPType<?> msgId = map.get(mp("msgId"));
             if (msgId instanceof MPBinary) {
-                builder.msgId(new InventoryVector(((MPBinary) msgId).getValue()));
+                builder.msgId(InventoryVector.fromHash(((MPBinary) msgId).getValue()));
             }
             builder.vote(str(map.get(mp("vote"))));
             return new Vote(builder);
diff --git a/core/src/main/java/ch/dissem/bitmessage/factory/V3MessageFactory.java b/core/src/main/java/ch/dissem/bitmessage/factory/V3MessageFactory.java
index a702e16..378f658 100644
--- a/core/src/main/java/ch/dissem/bitmessage/factory/V3MessageFactory.java
+++ b/core/src/main/java/ch/dissem/bitmessage/factory/V3MessageFactory.java
@@ -103,8 +103,10 @@ class V3MessageFactory {
             ByteArrayInputStream dataStream = new ByteArrayInputStream(data);
             payload = Factory.getObjectPayload(objectType, version, stream, dataStream, data.length);
         } catch (Exception e) {
-            LOG.trace("Could not parse object payload - using generic payload instead", e);
-            LOG.info(Strings.hex(data).toString());
+            if (LOG.isTraceEnabled()) {
+                LOG.trace("Could not parse object payload - using generic payload instead", e);
+                LOG.trace(Strings.hex(data).toString());
+            }
             payload = new GenericPayload(version, stream, data);
         }
 
@@ -165,7 +167,7 @@ class V3MessageFactory {
     }
 
     private static InventoryVector parseInventoryVector(InputStream stream) throws IOException {
-        return new InventoryVector(Decode.bytes(stream, 32));
+        return InventoryVector.fromHash(Decode.bytes(stream, 32));
     }
 
     private static NetworkAddress parseAddress(InputStream stream, boolean light) throws IOException {
diff --git a/core/src/test/java/ch/dissem/bitmessage/BitmessageContextTest.java b/core/src/test/java/ch/dissem/bitmessage/BitmessageContextTest.java
index 8051134..0702866 100644
--- a/core/src/test/java/ch/dissem/bitmessage/BitmessageContextTest.java
+++ b/core/src/test/java/ch/dissem/bitmessage/BitmessageContextTest.java
@@ -72,7 +72,7 @@ public class BitmessageContextTest {
 
                 @Override
                 public Item getItem(byte[] initialHash) {
-                    return items.get(new InventoryVector(initialHash));
+                    return items.get(InventoryVector.fromHash(initialHash));
                 }
 
                 @Override
@@ -86,12 +86,12 @@ public class BitmessageContextTest {
 
                 @Override
                 public void putObject(Item item) {
-                    items.put(new InventoryVector(cryptography().getInitialHash(item.object)), item);
+                    items.put(InventoryVector.fromHash(cryptography().getInitialHash(item.object)), item);
                 }
 
                 @Override
                 public void putObject(ObjectMessage object, long nonceTrialsPerByte, long extraBytes) {
-                    items.put(new InventoryVector(cryptography().getInitialHash(object)), new Item(object, nonceTrialsPerByte, extraBytes));
+                    items.put(InventoryVector.fromHash(cryptography().getInitialHash(object)), new Item(object, nonceTrialsPerByte, extraBytes));
                 }
 
                 @Override
diff --git a/core/src/test/java/ch/dissem/bitmessage/utils/TestUtils.java b/core/src/test/java/ch/dissem/bitmessage/utils/TestUtils.java
index fffaba8..6fadce4 100644
--- a/core/src/test/java/ch/dissem/bitmessage/utils/TestUtils.java
+++ b/core/src/test/java/ch/dissem/bitmessage/utils/TestUtils.java
@@ -66,7 +66,7 @@ public class TestUtils {
     public static InventoryVector randomInventoryVector() {
         byte[] bytes = new byte[32];
         RANDOM.nextBytes(bytes);
-        return new InventoryVector(bytes);
+        return InventoryVector.fromHash(bytes);
     }
 
     public static InputStream getResource(String resourceName) {
diff --git a/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcInventory.java b/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcInventory.java
index 13d3725..33b7290 100644
--- a/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcInventory.java
+++ b/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcInventory.java
@@ -69,7 +69,7 @@ public class JdbcInventory extends JdbcHelper implements Inventory {
                                     "WHERE expires > " + now(-5 * MINUTE) + " AND stream = " + stream)
                     ) {
                         while (rs.next()) {
-                            result.put(new InventoryVector(rs.getBytes("hash")), rs.getLong("expires"));
+                            result.put(InventoryVector.fromHash(rs.getBytes("hash")), rs.getLong("expires"));
                         }
                     } catch (SQLException e) {
                         LOG.error(e.getMessage(), e);
diff --git a/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcMessageRepository.java b/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcMessageRepository.java
index a918456..11c7028 100644
--- a/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcMessageRepository.java
+++ b/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcMessageRepository.java
@@ -110,7 +110,7 @@ public class JdbcMessageRepository extends AbstractMessageRepository implements
                 Plaintext.Builder builder = Plaintext.readWithoutSignature(type, data);
                 long id = rs.getLong("id");
                 builder.id(id);
-                builder.IV(new InventoryVector(iv));
+                builder.IV(InventoryVector.fromHash(iv));
                 builder.from(ctx.getAddressRepository().getAddress(rs.getString("sender")));
                 builder.to(ctx.getAddressRepository().getAddress(rs.getString("recipient")));
                 builder.ackData(rs.getBytes("ack_data"));