diff -rupN podofo-0.9.6/src/base/PdfDictionary.h podofo-0.9.6-new/src/base/PdfDictionary.h
--- podofo-0.9.6/src/base/PdfDictionary.h	2018-06-11 01:46:56.000000000 +0200
+++ podofo-0.9.6-new/src/base/PdfDictionary.h	2019-03-13 23:15:12.260138718 +0100
@@ -180,6 +180,21 @@ class PODOFO_API PdfDictionary : public
      */
     PdfObject* GetKey( const PdfName & key );
 
+    /** Get the key's value out of the dictionary.
+     *
+     * The returned value is a reference to the internal object in the dictionary
+     * so it MUST not be deleted. If the key is not found, this throws a PdfError
+     * exception with error code ePdfError_NoObject, instead of returning.
+     * This is intended to make code more readable by sparing (especially multiple)
+     * NULL checks.
+     *
+     *  \param key look for the key named key in the dictionary
+     *
+     *  \returns reference to the found value (never 0).
+     *  \throws PdfError(ePdfError_NoObject).
+     */
+    inline const PdfObject& MustGetKey( const PdfName & key ) const;
+
     pdf_int64 GetKeyAsLong( const PdfName & key, pdf_int64 lDefault = 0 ) const;
 
     double GetKeyAsReal( const PdfName & key, double dDefault = 0.0 ) const;
@@ -305,6 +320,18 @@ TKeyMap & PdfDictionary::GetKeys()
 // -----------------------------------------------------
 // 
 // -----------------------------------------------------
+
+const PdfObject& PdfDictionary::MustGetKey( const PdfName & key ) const
+{
+    const PdfObject* obj = GetKey( key );
+    if (!obj)
+        PODOFO_RAISE_ERROR( ePdfError_NoObject );
+    return *obj;
+}
+
+// -----------------------------------------------------
+//
+// -----------------------------------------------------
 void PdfDictionary::Write( PdfOutputDevice* pDevice, EPdfWriteMode eWriteMode, const PdfEncrypt* pEncrypt ) const 
 { 
     this->Write( pDevice, eWriteMode, pEncrypt, PdfName::KeyNull ); 
diff -rupN podofo-0.9.6/src/base/PdfEncrypt.cpp podofo-0.9.6-new/src/base/PdfEncrypt.cpp
--- podofo-0.9.6/src/base/PdfEncrypt.cpp	2017-02-26 21:48:19.000000000 +0100
+++ podofo-0.9.6-new/src/base/PdfEncrypt.cpp	2019-03-13 23:15:12.260138718 +0100
@@ -561,13 +561,13 @@ PdfEncrypt* PdfEncrypt::CreatePdfEncrypt
     try {
         PdfString sTmp;
         
-        lV           = static_cast<long>(pObject->GetDictionary().GetKey( PdfName("V") )->GetNumber());
-        rValue       = static_cast<int>(pObject->GetDictionary().GetKey( PdfName("R") )->GetNumber());
+        lV     = static_cast<long>(pObject->GetDictionary().MustGetKey( PdfName("V") ).GetNumber());
+        rValue = static_cast<int>( pObject->GetDictionary().MustGetKey( PdfName("R") ).GetNumber());
         
-        pValue       = static_cast<int>(pObject->GetDictionary().GetKey( PdfName("P") )->GetNumber());
+        pValue = static_cast<int>( pObject->GetDictionary().MustGetKey( PdfName("P") ).GetNumber());
         
-        oValue       = pObject->GetDictionary().GetKey( PdfName("O") )->GetString();        
-        uValue       = pObject->GetDictionary().GetKey( PdfName("U") )->GetString();
+        oValue =                   pObject->GetDictionary().MustGetKey( PdfName("O") ).GetString();
+        uValue =                   pObject->GetDictionary().MustGetKey( PdfName("U") ).GetString();
         
         if( pObject->GetDictionary().HasKey( PdfName("Length") ) )
         {
@@ -593,7 +593,7 @@ PdfEncrypt* PdfEncrypt::CreatePdfEncrypt
 			}
 		}
     } catch( PdfError & e ) {
-        e.AddToCallstack( __FILE__, __LINE__, "Invalid key in encryption dictionary" );
+        e.AddToCallstack( __FILE__, __LINE__, "Invalid or missing key in encryption dictionary" );
         throw e;
     }