diff --git a/ndn-cpp/security/identity/identity-storage.hpp b/ndn-cpp/security/identity/identity-storage.hpp
index 0e22432..db6ab0e 100644
--- a/ndn-cpp/security/identity/identity-storage.hpp
+++ b/ndn-cpp/security/identity/identity-storage.hpp
@@ -88,6 +88,7 @@
   /**
    * Get the public key DER blob from the identity storage.
    * @param keyName The name of the requested public key.
+   * @return The DER Blob.  If not found, return a Blob with a null pointer.
    */
   virtual Blob
   getKey(const Name& keyName) = 0;
@@ -125,7 +126,7 @@
    * Get a certificate from the identity storage.
    * @param certificateName The name of the requested certificate.
    * @param allowAny If false, only a valid certificate will be returned, otherwise validity is disregarded.
-   * @return The requested certificate.
+   * @return The requested certificate.  If not found, return a shared_ptr with a null pointer.
    */
   virtual ptr_lib::shared_ptr<Certificate> 
   getCertificate(const Name &certificateName, bool allowAny = false) = 0;
@@ -180,10 +181,10 @@
   /**
    * Set the default key name for the specified identity.
    * @param keyName The key name.
-   * @param identityName (optional) The identity name to check the keyName.
+   * @param identityNameCheck (optional) The identity name to check the keyName.
    */
   virtual void 
-  setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityName = Name()) = 0;
+  setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityNameCheck = Name()) = 0;
 
   /**
    * Set the default key name for the specified identity.
diff --git a/ndn-cpp/security/identity/memory-identity-storage.cpp b/ndn-cpp/security/identity/memory-identity-storage.cpp
index 81a96e9..bc2bd34 100644
--- a/ndn-cpp/security/identity/memory-identity-storage.cpp
+++ b/ndn-cpp/security/identity/memory-identity-storage.cpp
@@ -165,7 +165,7 @@
 }
 
 void 
-MemoryIdentityStorage::setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityName)
+MemoryIdentityStorage::setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityNameCheck)
 {
 #if 1
   throw std::runtime_error("MemoryIdentityStorage::setDefaultKeyNameForIdentity not implemented");
diff --git a/ndn-cpp/security/identity/memory-identity-storage.hpp b/ndn-cpp/security/identity/memory-identity-storage.hpp
index 980f78d..ba0ea5a 100644
--- a/ndn-cpp/security/identity/memory-identity-storage.hpp
+++ b/ndn-cpp/security/identity/memory-identity-storage.hpp
@@ -84,6 +84,7 @@
   /**
    * Get the public key DER blob from the identity storage.
    * @param keyName The name of the requested public key.
+   * @return The DER Blob.  If not found, return a Blob with a null pointer.
    */
   virtual Blob
   getKey(const Name& keyName);
@@ -121,7 +122,7 @@
    * Get a certificate from the identity storage.
    * @param certificateName The name of the requested certificate.
    * @param allowAny If false, only a valid certificate will be returned, otherwise validity is disregarded.
-   * @return The requested certificate.
+   * @return The requested certificate.  If not found, return a shared_ptr with a null pointer.
    */
   virtual ptr_lib::shared_ptr<Certificate> 
   getCertificate(const Name &certificateName, bool allowAny = false);
@@ -165,10 +166,10 @@
   /**
    * Set the default key name for the specified identity.
    * @param keyName The key name.
-   * @param identityName (optional) The identity name to check the keyName.
+   * @param identityNameCheck (optional) The identity name to check the keyName.
    */
   virtual void 
-  setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityName = Name());
+  setDefaultKeyNameForIdentity(const Name& keyName, const Name& identityNameCheck = Name());
 
   /**
    * Set the default key name for the specified identity.