diff --git a/src/share/classes/com/sun/org/apache/xml/internal/security/Init.java b/src/share/classes/com/sun/org/apache/xml/internal/security/Init.java
index 308d517a2c47f6f4bb5091725ca1bebab0317604..d1ebe5fc730502dd1a2cd81ea1bc03d36145f8d6 100644
--- a/src/share/classes/com/sun/org/apache/xml/internal/security/Init.java
+++ b/src/share/classes/com/sun/org/apache/xml/internal/security/Init.java
@@ -153,8 +153,8 @@ public final class Init {
                         break;
                 }
             }
-                        for (Node el=config.getFirstChild();el!=null;el=el.getNextSibling()) {
-                if (!(el instanceof Element)) {
+            for (Node el=config.getFirstChild();el!=null;el=el.getNextSibling()) {
+                if (el.getNodeType() != Node.ELEMENT_NODE) {
                         continue;
                 }
                 String tag=el.getLocalName();
diff --git a/src/share/classes/com/sun/org/apache/xml/internal/security/c14n/implementations/CanonicalizerBase.java b/src/share/classes/com/sun/org/apache/xml/internal/security/c14n/implementations/CanonicalizerBase.java
index 77024c23403e7703f4af64bedcee83270424be8b..2f5f28904d201966daf089e668960caa62fb5a8c 100644
--- a/src/share/classes/com/sun/org/apache/xml/internal/security/c14n/implementations/CanonicalizerBase.java
+++ b/src/share/classes/com/sun/org/apache/xml/internal/security/c14n/implementations/CanonicalizerBase.java
@@ -205,7 +205,7 @@ public abstract class CanonicalizerBase extends CanonicalizerSpi {
         try {
          NameSpaceSymbTable ns=new NameSpaceSymbTable();
          int nodeLevel=NODE_BEFORE_DOCUMENT_ELEMENT;
-         if (rootNode instanceof Element) {
+         if (rootNode != null && rootNode.getNodeType() == Node.ELEMENT_NODE) {
                 //Fills the nssymbtable with the definitions of the parent of the root subnode
                 getParentNameSpaces((Element)rootNode,ns);
                 nodeLevel=NODE_NOT_BEFORE_OR_AFTER_DOCUMENT_ELEMENT;
@@ -335,7 +335,7 @@ public abstract class CanonicalizerBase extends CanonicalizerSpi {
                                 return;
                         sibling=parentNode.getNextSibling();
                         parentNode=parentNode.getParentNode();
-                        if (!(parentNode instanceof Element)) {
+                        if (parentNode !=null && parentNode.getNodeType() != Node.ELEMENT_NODE) {
                                 documentLevel=NODE_AFTER_DOCUMENT_ELEMENT;
                                 parentNode=null;
                         }
@@ -391,7 +391,7 @@ public abstract class CanonicalizerBase extends CanonicalizerSpi {
                 return;
         boolean currentNodeIsVisible = false;
         NameSpaceSymbTable ns=new  NameSpaceSymbTable();
-        if (currentNode instanceof Element)
+        if (currentNode != null && currentNode.getNodeType() == Node.ELEMENT_NODE)
                 getParentNameSpaces((Element)currentNode,ns);
         Node sibling=null;
         Node parentNode=null;
@@ -512,7 +512,7 @@ public abstract class CanonicalizerBase extends CanonicalizerSpi {
                                 return;
                         sibling=parentNode.getNextSibling();
                         parentNode=parentNode.getParentNode();
-                        if (!(parentNode instanceof Element)) {
+                        if (parentNode != null && parentNode.getNodeType() != Node.ELEMENT_NODE) {
                                 parentNode=null;
                                 documentLevel=NODE_AFTER_DOCUMENT_ELEMENT;
                         }
@@ -594,18 +594,14 @@ public abstract class CanonicalizerBase extends CanonicalizerSpi {
         final void getParentNameSpaces(Element el,NameSpaceSymbTable ns)  {
                 List<Element> parents=new ArrayList<Element>(10);
                 Node n1=el.getParentNode();
-                if (!(n1 instanceof Element)) {
+                if (n1 == null || n1.getNodeType() != Node.ELEMENT_NODE) {
                         return;
                 }
                 //Obtain all the parents of the elemnt
-                Element parent=(Element) n1;
-                while (parent!=null) {
-                        parents.add(parent);
-                        Node n=parent.getParentNode();
-                        if (!(n instanceof Element )) {
-                                break;
-                        }
-                        parent=(Element)n;
+                Node parent = n1;
+                while (parent!=null && parent.getNodeType() == Node.ELEMENT_NODE) {
+                        parents.add((Element)parent);
+                        parent = parent.getParentNode();
                 }
                 //Visit them in reverse order.
                 ListIterator<Element> it=parents.listIterator(parents.size());
diff --git a/src/share/classes/com/sun/org/apache/xml/internal/security/encryption/XMLCipher.java b/src/share/classes/com/sun/org/apache/xml/internal/security/encryption/XMLCipher.java
index 8479835c901b80e0e287bcf432bcc5395061bb1e..b8be1a505ed35aacb458fd515352e41b6da09c11 100644
--- a/src/share/classes/com/sun/org/apache/xml/internal/security/encryption/XMLCipher.java
+++ b/src/share/classes/com/sun/org/apache/xml/internal/security/encryption/XMLCipher.java
@@ -1445,7 +1445,7 @@ public class XMLCipher {
                 // The de-serialiser returns a fragment whose children we need to
                 // take on.
 
-                if (sourceParent instanceof Document) {
+                if (sourceParent != null && sourceParent.getNodeType() == Node.DOCUMENT_NODE) {
 
                     // If this is a content decryption, this may have problems
 
diff --git a/src/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/implementations/RetrievalMethodResolver.java b/src/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/implementations/RetrievalMethodResolver.java
index 80674426281400324ada70ad15881315f3c5f4b2..fec12b3b1bf5422f315d54ff51507c05ea4b8adc 100644
--- a/src/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/implementations/RetrievalMethodResolver.java
+++ b/src/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/implementations/RetrievalMethodResolver.java
@@ -283,7 +283,7 @@ public class RetrievalMethodResolver extends KeyResolverSpi {
            Element e=null;
            while (it.hasNext()) {
                    Node currentNode=it.next();
-                   if (currentNode instanceof Element) {
+                   if (currentNode != null && currentNode.getNodeType() == Node.ELEMENT_NODE) {
                            e=(Element)currentNode;
                            break;
                    }
@@ -292,14 +292,14 @@ public class RetrievalMethodResolver extends KeyResolverSpi {
            List<Element> parents=new ArrayList<Element>(10);
 
                 //Obtain all the parents of the elemnt
-                do {
+                while (e != null) {
                         parents.add(e);
                         Node n=e.getParentNode();
-                        if (!(n instanceof Element )) {
+                        if (n == null || n.getNodeType() != Node.ELEMENT_NODE) {
                                 break;
                         }
                         e=(Element)n;
-                } while (e!=null);
+                }
                 //Visit them in reverse order.
                 ListIterator<Element> it2=parents.listIterator(parents.size()-1);
                 Element ele=null;
diff --git a/src/share/classes/com/sun/org/apache/xml/internal/security/utils/IdResolver.java b/src/share/classes/com/sun/org/apache/xml/internal/security/utils/IdResolver.java
index 2fba84559687d56f3a5078b1af070a95157a2378..4ee51ac92ab69456362cfb0aa5c5ed7abf49c62c 100644
--- a/src/share/classes/com/sun/org/apache/xml/internal/security/utils/IdResolver.java
+++ b/src/share/classes/com/sun/org/apache/xml/internal/security/utils/IdResolver.java
@@ -225,7 +225,7 @@ public class IdResolver {
         } while (sibling==null  && parentNode!=null) {
                         sibling=parentNode.getNextSibling();
                         parentNode=parentNode.getParentNode();
-                        if (!(parentNode instanceof Element)) {
+                        if (parentNode != null && parentNode.getNodeType() != Node.ELEMENT_NODE) {
                                 parentNode=null;
                         }
                 }