diff --git a/Libraries/Opc.Ua.Gds.Client.Common/GlobalDiscoveryServerClient.cs b/Libraries/Opc.Ua.Gds.Client.Common/GlobalDiscoveryServerClient.cs
index 9e5084272..68d5c8985 100644
--- a/Libraries/Opc.Ua.Gds.Client.Common/GlobalDiscoveryServerClient.cs
+++ b/Libraries/Opc.Ua.Gds.Client.Common/GlobalDiscoveryServerClient.cs
@@ -584,6 +584,36 @@ public NodeId RegisterApplication(ApplicationRecordDataType application)
             return null;
         }
 
+        /// <summary>
+        /// Checks the provided certificate for validity
+        /// </summary>
+        /// <param name="certificate">The DER encoded form of the Certificate to check.</param>
+        /// <param name="certificateStatus">The first error encountered when validating the Certificate.</param>
+        /// <param name="validityTime">When the result expires and should be rechecked. DateTime.MinValue if this is unknown.</param>
+        public void CheckRevocationStatus(byte[] certificate,
+            out StatusCode certificateStatus,
+            out DateTime validityTime)
+        {
+            certificateStatus = StatusCodes.Good;
+            validityTime = DateTime.MinValue;
+
+            if (!IsConnected)
+            {
+                Connect();
+            }
+
+            var outputArguments = Session.Call(
+                ExpandedNodeId.ToNodeId(Opc.Ua.Gds.ObjectIds.Directory, Session.NamespaceUris),
+                ExpandedNodeId.ToNodeId(Opc.Ua.Gds.MethodIds.CertificateDirectoryType_CheckRevocationStatus, Session.NamespaceUris),
+                certificate);
+
+            if (outputArguments.Count >= 2)
+            {
+                certificateStatus = (StatusCode)outputArguments[0];
+                validityTime = (DateTime)outputArguments[1];
+            }
+        }
+
         /// <summary>
         /// Updates the application.
         /// </summary>
diff --git a/Libraries/Opc.Ua.Gds.Server.Common/ApplicationsNodeManager.cs b/Libraries/Opc.Ua.Gds.Server.Common/ApplicationsNodeManager.cs
index c5d9c92da..87dd81d3c 100644
--- a/Libraries/Opc.Ua.Gds.Server.Common/ApplicationsNodeManager.cs
+++ b/Libraries/Opc.Ua.Gds.Server.Common/ApplicationsNodeManager.cs
@@ -162,7 +162,7 @@ public override NodeId New(ISystemContext context, NodeState node)
         }
         #endregion
 
-        #region Private methods
+        #region Private Methods
         private NodeId GetTrustListId(NodeId certificateGroupId)
         {
 
@@ -381,6 +381,8 @@ protected override NodeState AddBehaviourToPredefinedNode(ISystemContext context
 
                     Opc.Ua.Gds.CertificateDirectoryState activeNode = new Opc.Ua.Gds.CertificateDirectoryState(passiveNode.Parent);
 
+                    activeNode.CheckRevocationStatus = new CheckRevocationStatusMethodState(passiveNode.Parent);
+
                     activeNode.Create(context, passiveNode);
                     activeNode.QueryServers.OnCall = new QueryServersMethodStateMethodCallHandler(OnQueryServers);
                     activeNode.QueryApplications.OnCall = new QueryApplicationsMethodStateMethodCallHandler(OnQueryApplications);
@@ -395,6 +397,8 @@ protected override NodeState AddBehaviourToPredefinedNode(ISystemContext context
                     activeNode.GetTrustList.OnCall = new GetTrustListMethodStateMethodCallHandler(OnGetTrustList);
                     activeNode.GetCertificateStatus.OnCall = new GetCertificateStatusMethodStateMethodCallHandler(OnGetCertificateStatus);
                     activeNode.StartSigningRequest.OnCall = new StartSigningRequestMethodStateMethodCallHandler(OnStartSigningRequest);
+                    activeNode.CheckRevocationStatus.OnCall = new CheckRevocationStatusMethodStateMethodCallHandler(OnCheckRevocationStatus);
+
                     // TODO
                     //activeNode.RevokeCertificate.OnCall = new RevokeCertificateMethodStateMethodCallHandler(OnRevokeCertificate);
 
@@ -584,6 +588,41 @@ private ServiceResult OnGetApplication(
             return ServiceResult.Good;
         }
 
+        private ServiceResult OnCheckRevocationStatus(
+        ISystemContext context,
+        MethodState method,
+        NodeId objectId,
+        byte[] certificate,
+        ref StatusCode certificateStatus,
+        ref DateTime validityTime)
+        {
+            AuthorizationHelper.HasAuthenticatedSecureChannel(context);
+
+            //create CertificateValidator initialized with GDS CAs
+            var certificateValidator = new CertificateValidator();
+            var authorities = new CertificateTrustList() {
+                StorePath = m_globalDiscoveryServerConfiguration.AuthoritiesStorePath,
+                StoreType = CertificateStoreIdentifier.DetermineStoreType(m_globalDiscoveryServerConfiguration.AuthoritiesStorePath)
+            };
+            certificateValidator.Update(null, authorities, null);
+
+            //TODO return validityTime of Certificate once CertificateValidator supports it
+            validityTime = DateTime.MinValue;
+
+            using (var x509 = new X509Certificate2(certificate))
+            {
+                try
+                {
+                    certificateValidator.Validate(x509);
+                }
+                catch (ServiceResultException se)
+                {
+                    certificateStatus = se.StatusCode;
+                }
+            }
+            return ServiceResult.Good;
+        }
+
         private ServiceResult CheckHttpsDomain(ApplicationRecordDataType application, string commonName)
         {
             if (application.ApplicationType == ApplicationType.Client)
diff --git a/Libraries/Opc.Ua.Gds.Server.Common/RoleBasedUserManagement/AuthorizationHelper.cs b/Libraries/Opc.Ua.Gds.Server.Common/RoleBasedUserManagement/AuthorizationHelper.cs
index 4bf0e86e2..f1cbc971c 100644
--- a/Libraries/Opc.Ua.Gds.Server.Common/RoleBasedUserManagement/AuthorizationHelper.cs
+++ b/Libraries/Opc.Ua.Gds.Server.Common/RoleBasedUserManagement/AuthorizationHelper.cs
@@ -51,95 +51,110 @@ internal static class AuthorizationHelper
         /// <param name="roles">all allowed roles, if wanted include <see cref="GdsRole.ApplicationSelfAdmin"/></param>
         /// <param name="applicationId">If <see cref="GdsRole.ApplicationSelfAdmin"/> is allowed specifies the id of the Application-Entry to access</param>
         public static void HasAuthorization(ISystemContext context, IEnumerable<Role> roles, [Optional] NodeId applicationId)
-    {
-        if (context != null)
         {
-            List<Role> allowedRoles = roles.ToList();
-            bool selfAdmin = allowedRoles.Remove(GdsRole.ApplicationSelfAdmin);
-
-            //if true access is allowed
-            if (HasRole(context.UserIdentity, allowedRoles))
-                return;
-
-            if (selfAdmin)
+            if (context != null)
             {
-                //if true access to own application is allowed
-                if (CheckSelfAdminPrivilege(context.UserIdentity, applicationId))
+                List<Role> allowedRoles = roles.ToList();
+                bool selfAdmin = allowedRoles.Remove(GdsRole.ApplicationSelfAdmin);
+
+                //if true access is allowed
+                if (HasRole(context.UserIdentity, allowedRoles))
                     return;
+
+                if (selfAdmin)
+                {
+                    //if true access to own application is allowed
+                    if (CheckSelfAdminPrivilege(context.UserIdentity, applicationId))
+                        return;
+                }
+                throw new ServiceResultException(StatusCodes.BadUserAccessDenied, $"At least one of the Roles {string.Join(", ", roles)} is required to call the method");
             }
-            throw new ServiceResultException(StatusCodes.BadUserAccessDenied, $"At least one of the Roles {string.Join(", ", roles)} is required to call the method");
         }
-    }
-    /// <summary>
-    /// Checks if the current session (context) is allowed to access the trust List (has roles CertificateAuthorityAdmin, SecurityAdmin or <see cref="GdsRole.ApplicationSelfAdmin"/>)
-    /// </summary>
-    /// <param name="context">the current <see cref="ISystemContext"/></param>
-    /// <param name="trustedStorePath">path of the trustList, needed to check for Application Self Admin priviledge</param>
-    /// <param name="certTypeMap">all supported cert types, needed to check for Application Self Admin priviledge </param>
-    /// <param name="applicationsDatabase">all registered applications  <see cref="IApplicationsDatabase"/> , needed to check for Application Self Admin priviledge </param>
-    /// <exception cref="ServiceResultException"></exception>
-    public static void HasTrustListAccess(ISystemContext context, string trustedStorePath, Dictionary<NodeId, string> certTypeMap, IApplicationsDatabase applicationsDatabase)
-    {
-        var roles = new List<Role> { GdsRole.CertificateAuthorityAdmin, Role.SecurityAdmin };
-        if (HasRole(context.UserIdentity, roles))
-            return;
-
-        if (!string.IsNullOrEmpty(trustedStorePath) && certTypeMap != null && applicationsDatabase != null &&
-            CheckSelfAdminPrivilege(context.UserIdentity, trustedStorePath, certTypeMap, applicationsDatabase))
-            return;
-
-        throw new ServiceResultException(StatusCodes.BadUserAccessDenied, $"At least one of the Roles {string.Join(", ", roles)} or ApplicationSelfAdminPrivilege is required to use the TrustList");
-    }
+        /// <summary>
+        /// Checks if the current session (context) is allowed to access the trust List (has roles CertificateAuthorityAdmin, SecurityAdmin or <see cref="GdsRole.ApplicationSelfAdmin"/>)
+        /// </summary>
+        /// <param name="context">the current <see cref="ISystemContext"/></param>
+        /// <param name="trustedStorePath">path of the trustList, needed to check for Application Self Admin priviledge</param>
+        /// <param name="certTypeMap">all supported cert types, needed to check for Application Self Admin priviledge </param>
+        /// <param name="applicationsDatabase">all registered applications  <see cref="IApplicationsDatabase"/> , needed to check for Application Self Admin priviledge </param>
+        /// <exception cref="ServiceResultException"></exception>
+        public static void HasTrustListAccess(ISystemContext context, string trustedStorePath, Dictionary<NodeId, string> certTypeMap, IApplicationsDatabase applicationsDatabase)
+        {
+            var roles = new List<Role> { GdsRole.CertificateAuthorityAdmin, Role.SecurityAdmin };
+            if (HasRole(context.UserIdentity, roles))
+                return;
 
-    private static bool HasRole(IUserIdentity userIdentity, IEnumerable<Role> roles)
-    {
-        RoleBasedIdentity identity = userIdentity as RoleBasedIdentity;
+            if (!string.IsNullOrEmpty(trustedStorePath) && certTypeMap != null && applicationsDatabase != null &&
+                CheckSelfAdminPrivilege(context.UserIdentity, trustedStorePath, certTypeMap, applicationsDatabase))
+                return;
 
-        if (identity != null)
+            throw new ServiceResultException(StatusCodes.BadUserAccessDenied, $"At least one of the Roles {string.Join(", ", roles)} or ApplicationSelfAdminPrivilege is required to use the TrustList");
+        }
+        /// <summary>
+        /// Checks if current session (context) is connected using a secure channel
+        /// </summary>
+        /// <param name="context">the current <see cref="ISystemContext"/></param>
+        /// <exception cref="ServiceResultException"></exception>
+        public static void HasAuthenticatedSecureChannel(ISystemContext context)
         {
-            foreach (Role role in roles)
+            OperationContext operationContext = (context as SystemContext)?.OperationContext as OperationContext;
+            if (operationContext != null)
             {
-                if ((identity.Roles.Contains(role)))
+                if (operationContext.ChannelContext?.EndpointDescription?.SecurityMode != MessageSecurityMode.SignAndEncrypt)
                 {
-                    return true;
+                    throw new ServiceResultException(StatusCodes.BadUserAccessDenied, "Method has to be called from an authenticated secure channel.");
                 }
             }
         }
-        return false;
-    }
+        private static bool HasRole(IUserIdentity userIdentity, IEnumerable<Role> roles)
+        {
+            RoleBasedIdentity identity = userIdentity as RoleBasedIdentity;
 
-    private static bool CheckSelfAdminPrivilege(IUserIdentity userIdentity, NodeId applicationId)
-    {
-        if (applicationId is null || applicationId.IsNullNodeId)
+            if (identity != null)
+            {
+                foreach (Role role in roles)
+                {
+                    if ((identity.Roles.Contains(role)))
+                    {
+                        return true;
+                    }
+                }
+            }
             return false;
+        }
 
-        GdsRoleBasedIdentity identity = userIdentity as GdsRoleBasedIdentity;
-        if (identity != null)
+        private static bool CheckSelfAdminPrivilege(IUserIdentity userIdentity, NodeId applicationId)
         {
-            //self Admin only has access to own application
-            if (identity.ApplicationId == applicationId)
+            if (applicationId is null || applicationId.IsNullNodeId)
+                return false;
+
+            GdsRoleBasedIdentity identity = userIdentity as GdsRoleBasedIdentity;
+            if (identity != null)
             {
-                return true;
+                //self Admin only has access to own application
+                if (identity.ApplicationId == applicationId)
+                {
+                    return true;
+                }
             }
+            return false;
         }
-        return false;
-    }
 
-    private static bool CheckSelfAdminPrivilege(IUserIdentity userIdentity, string trustedStorePath, Dictionary<NodeId, string> certTypeMap, IApplicationsDatabase applicationsDatabase)
-    {
-        GdsRoleBasedIdentity identity = userIdentity as GdsRoleBasedIdentity;
-        if (identity != null)
+        private static bool CheckSelfAdminPrivilege(IUserIdentity userIdentity, string trustedStorePath, Dictionary<NodeId, string> certTypeMap, IApplicationsDatabase applicationsDatabase)
         {
-            foreach (var certType in certTypeMap.Values)
+            GdsRoleBasedIdentity identity = userIdentity as GdsRoleBasedIdentity;
+            if (identity != null)
             {
-                applicationsDatabase.GetApplicationTrustLists(identity.ApplicationId, certType, out var trustListId);
-                if (trustedStorePath == trustListId)
+                foreach (var certType in certTypeMap.Values)
                 {
-                    return true;
+                    applicationsDatabase.GetApplicationTrustLists(identity.ApplicationId, certType, out var trustListId);
+                    if (trustedStorePath == trustListId)
+                    {
+                        return true;
+                    }
                 }
             }
+            return false;
         }
-        return false;
     }
 }
-}
diff --git a/Tests/Opc.Ua.Gds.Tests/ClientTest.cs b/Tests/Opc.Ua.Gds.Tests/ClientTest.cs
index 334b60fbb..c58d2a89c 100644
--- a/Tests/Opc.Ua.Gds.Tests/ClientTest.cs
+++ b/Tests/Opc.Ua.Gds.Tests/ClientTest.cs
@@ -1297,6 +1297,19 @@ public void GetInvalidCertificateStatus()
             }
         }
 
+        [Test, Order(700)]
+        public void CheckGoodRevocationStatus()
+        {
+            AssertIgnoreTestWithoutGoodRegistration();
+            ConnectGDS(false);
+            foreach (var application in m_goodApplicationTestSet)
+            {
+                m_gdsClient.GDSClient.CheckRevocationStatus(application.Certificate, out StatusCode certificateStatus, out DateTime validityTime);
+                Assert.AreEqual(StatusCodes.Good, certificateStatus.Code);
+                Assert.NotNull(validityTime);
+            }
+        }
+
         [Test, Order(900)]
         public void UnregisterGoodApplications()
         {
@@ -1308,6 +1321,19 @@ public void UnregisterGoodApplications()
             }
         }
 
+        [Test, Order(910)]
+        public void CheckRevocationStatusUnregisteredApplications()
+        {
+            AssertIgnoreTestWithoutGoodRegistration();
+            ConnectGDS(false);
+            foreach (var application in m_goodApplicationTestSet)
+            {
+                m_gdsClient.GDSClient.CheckRevocationStatus(application.Certificate, out StatusCode certificateStatus, out DateTime validityTime);
+                Assert.AreEqual(StatusCodes.BadCertificateRevoked, certificateStatus.Code);
+                Assert.NotNull(validityTime);
+            }
+        }
+
         [Test, Order(910)]
         public void UnregisterInvalidApplications()
         {