diff --git a/pdf-toolkit-repo/src/main/java/org/alfresco/extension/pdftoolkit/service/PDFToolkitServiceImpl.java b/pdf-toolkit-repo/src/main/java/org/alfresco/extension/pdftoolkit/service/PDFToolkitServiceImpl.java
index 154813e..7d8c3c5 100644
--- a/pdf-toolkit-repo/src/main/java/org/alfresco/extension/pdftoolkit/service/PDFToolkitServiceImpl.java
+++ b/pdf-toolkit-repo/src/main/java/org/alfresco/extension/pdftoolkit/service/PDFToolkitServiceImpl.java
@@ -53,6 +53,7 @@
 import org.apache.pdfbox.multipdf.PDFMergerUtility;
 import org.apache.pdfbox.multipdf.Splitter;
 import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.encryption.InvalidPasswordException;
 import org.springframework.extensions.surf.util.I18NUtil;
 
 import com.itextpdf.text.Document;
@@ -125,6 +126,9 @@ public NodeRef appendPDF(NodeRef targetNodeRef, Map<String, Serializable> params
             pdf = PDDocument.load(is);
             pdfTarget = PDDocument.load(tis);
             
+            pdf = decryptPdf(pdfTarget, is);
+            pdfTarget = decryptPdf(pdfTarget, tis);
+            
             // Append the PDFs
             PDFMergerUtility merger = new PDFMergerUtility();
             merger.appendDocument(pdfTarget, pdf);
@@ -216,6 +220,17 @@ public NodeRef appendPDF(NodeRef targetNodeRef, Map<String, Serializable> params
         
         return destinationNode;
     }
+
+	private PDDocument decryptPdf(PDDocument pdf, InputStream tis) throws IOException, InvalidPasswordException {
+		// if the document is encrypted, try to remove its protection by using the "" (EMPTY) password 
+		// as an attempt before failing during the append operation
+		if(pdf.isEncrypted()) {
+			pdf.close();
+			pdf = PDDocument.load(tis, "");
+			pdf.setAllSecurityToBeRemoved(true);
+		}
+		return pdf;
+	}
     
 	@Override
 	public NodeRef encryptPDF(NodeRef targetNodeRef, Map<String, Serializable> params)