diff --git a/src/security/identity/identity-manager.cpp b/src/security/identity/identity-manager.cpp
index ce6ff21..0c57212 100644
--- a/src/security/identity/identity-manager.cpp
+++ b/src/security/identity/identity-manager.cpp
@@ -30,9 +30,6 @@
 
 namespace ndn {
 
-const ptr_lib::shared_ptr<IdentityStorage>   IdentityManager::DefaultIdentityStorage   = ptr_lib::shared_ptr<IdentityStorage>();
-const ptr_lib::shared_ptr<PrivateKeyStorage> IdentityManager::DefaultPrivateKeyStorage = ptr_lib::shared_ptr<PrivateKeyStorage>();
-
 IdentityManager::IdentityManager(const ptr_lib::shared_ptr<IdentityStorage>   &identityStorage   /* = DefaultIdentityStorage */,
                                  const ptr_lib::shared_ptr<PrivateKeyStorage> &privateKeyStorage /* = DefaultPrivateKeyStorage */)
   : identityStorage_(identityStorage)
diff --git a/src/security/identity/osx-private-key-storage.cpp b/src/security/identity/osx-private-key-storage.cpp
index f41f89f..fec7671 100644
--- a/src/security/identity/osx-private-key-storage.cpp
+++ b/src/security/identity/osx-private-key-storage.cpp
@@ -277,13 +277,19 @@
 
     if (!signature) throw Error("Signature is NULL!\n");
 
-    return Block(Tlv::SignatureValue, ptr_lib::make_shared<Buffer>(CFDataGetBytePtr(signature), CFDataGetLength(signature)));
+    return Block(Tlv::SignatureValue,
+                 ptr_lib::make_shared<Buffer>(CFDataGetBytePtr(signature), CFDataGetLength(signature)));
   }
 
   void
   OSXPrivateKeyStorage::sign(Data &data,
                              const Name& keyName, DigestAlgorithm digestAlgorithm/* = DIGEST_ALGORITHM_SHA256 */)
   {
+    const uint8_t *begin = data.wireEncode().value();
+    const uint8_t *end   = &*data.getSignature().getInfo().end();
+    
+    data.setSignature
+      (sign(begin, end-begin, keyName, digestAlgorithm));
   }
 
   ConstBufferPtr