diff --git a/Stack/Opc.Ua.Core/Security/Certificates/X509AuthorityKeyIdentifierExtension.cs b/Stack/Opc.Ua.Core/Security/Certificates/X509AuthorityKeyIdentifierExtension.cs
index 8816980465..4ba5b6b99c 100644
--- a/Stack/Opc.Ua.Core/Security/Certificates/X509AuthorityKeyIdentifierExtension.cs
+++ b/Stack/Opc.Ua.Core/Security/Certificates/X509AuthorityKeyIdentifierExtension.cs
@@ -160,6 +160,7 @@ namespace Opc.Ua
         public string KeyId
         {
             get { return m_keyId; }
+            private set { m_keyId = value; }
         }
 
         /// <summary>
@@ -168,6 +169,7 @@ namespace Opc.Ua
         public string[] AuthorityNames
         {
             get { return m_authorityNames; }
+            private set { m_authorityNames = value; }
         }
 
         /// <summary>
@@ -176,6 +178,7 @@ namespace Opc.Ua
         public string SerialNumber
         {
             get { return m_serialNumber; }
+            private set { m_serialNumber = value; }
         }
         #endregion
 
diff --git a/Stack/Opc.Ua.Core/Security/Certificates/X509CRL.cs b/Stack/Opc.Ua.Core/Security/Certificates/X509CRL.cs
index 830dfe4188..82f1c19ec3 100644
--- a/Stack/Opc.Ua.Core/Security/Certificates/X509CRL.cs
+++ b/Stack/Opc.Ua.Core/Security/Certificates/X509CRL.cs
@@ -114,8 +114,19 @@ namespace Opc.Ua
         public bool VerifySignature(X509Certificate2 issuer, bool throwOnError)
         {
             m_issuer = issuer;
-            Org.BouncyCastle.X509.X509Certificate bccert = new X509CertificateParser().ReadCertificate(issuer.RawData);
-            m_crl.Verify(bccert.GetPublicKey());
+            try
+            {
+                Org.BouncyCastle.X509.X509Certificate bccert = new X509CertificateParser().ReadCertificate(issuer.RawData);
+                m_crl.Verify(bccert.GetPublicKey());
+            }
+            catch (Exception)
+            {
+                if (throwOnError)
+                {
+                    throw new ServiceResultException(StatusCodes.BadCertificateInvalid, "Could not verify signature on CRL.");
+                }
+                return false;
+            }
             return true;
         }