diff --git a/lib/transport.js b/lib/transport.js
index 03104de3..bc6fa3c3 100644
--- a/lib/transport.js
+++ b/lib/transport.js
@@ -1,5 +1,6 @@
 import co from 'co';
 import querystring from 'querystring';
+import { AuthCalc } from 'httpauth';
 
 import XMLHttpRequest from './xmlhttprequest';
 
@@ -24,12 +25,19 @@ export class Transport {
   send() {}
 }
 
+/*
+Standard HTTP authentication
+- supports both Basic and Digest authentication
+- chooses the method automatically
+- works better with CORS (passes Authorization directly)
+*/
 export class Basic extends Transport {
   /**
    * @param {dav.Credentials} credentials user authorization.
    */
   constructor(credentials) {
     super(credentials);
+    this.auth = new AuthCalc(this.credentials.username, this.credentials.password);
   }
 
   send(request, url, options) {
@@ -39,25 +47,39 @@ export class Basic extends Transport {
       let transformResponse = request.transformResponse;
       let onerror = request.onerror;
 
-      let xhr = new XMLHttpRequest();
-      if (sandbox) sandbox.add(xhr);
-      xhr.open(
-        request.method,
-        url,
-        true /* async */,
-        this.credentials.username,
-        this.credentials.password
-      );
+      let result;
+      let retryCnt = 1;
+      while (retryCnt >= 0) {
+        retryCnt--;
+        let xhr = new XMLHttpRequest();
+        if (sandbox) sandbox.add(xhr);
+          xhr.open(
+            request.method,
+            url,
+            true /* async */
+            //WITHOUT login and password
+            //NO  "withCredentials"
+          );
 
-      if (transformRequest) transformRequest(xhr);
+        this.auth.sign(xhr.request, {url: url, type: request.method, data: request.requestData});
 
-      let result;
-      try {
-        yield xhr.send(request.requestData);
-        result = transformResponse ? transformResponse(xhr) : xhr;
-      } catch (error) {
-        if (onerror) onerror(error);
-        throw error;
+        if (transformRequest) transformRequest(xhr);
+
+        try {
+          yield xhr.send(request.requestData);
+          result = transformResponse ? transformResponse(xhr) : xhr;
+          break; //of repeat loop
+        } catch (error) {
+          console.debug("dav.Transport.Basic::OnError: "+xhr.request.status);
+          //Authentication required? Reinitialize the auth context
+          if (xhr.request.status === 401 || xhr.request.status === 407) {
+            console.debug("Reinitializing the auth context...");
+            this.auth.updateServerResponse(xhr.request);
+            continue; //try again
+          }
+          if (onerror) onerror(error);
+          throw error;
+        }
       }
 
       return result;
diff --git a/package.json b/package.json
index a307f946..80a50c85 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,7 @@
     "@babel/polyfill": "^7.0.0",
     "co": "^4.6.0",
     "debug": "^4.1.1",
+    "httpauth": "github:himselfv/httpauth",
     "xmldom": "^0.1.27",
     "xmlhttprequest": "^1.8.0"
   },