diff --git a/include/templates.h b/include/templates.h
index 0742c2c..aa80e49 100644
--- a/include/templates.h
+++ b/include/templates.h
@@ -89,4 +89,13 @@
   "		</ul>" \
   FOOTER
 
+#define ERROR_401 \
+  HEADER1 \
+  "		<title>Error 401 - Unauthorized</title>" \
+  HEADER2 \
+  "		<h1>Error 401 - Unauthorized</h1>" \
+  "		<p>You are not authorized to see the requested content.<p>" \
+  "		<p>Enter the correct username and password!<p>" \
+  FOOTER
+
 #endif // TEMPLATES_H
diff --git a/src/main.c b/src/main.c
index b9e2e25..d582d95 100644
--- a/src/main.c
+++ b/src/main.c
@@ -45,6 +45,8 @@
 #define DEFAULT_PORT 8888
 
 char *shareRoot;
+char *password;
+struct MHD_Response *error401Response;
 struct MHD_Response *error403Response;
 struct MHD_Response *error404Response;
 struct MHD_Response *error500Response;
@@ -419,6 +421,36 @@ int key_value_iterator(void *cls,
   }
 }
 
+// returns 1 on successful authentication and 0 when auth. failed
+static int check_authorization(struct MHD_Connection *connection) {
+  char *auth_pass;
+  char *auth_user;
+  int fail;
+
+  if(password == NULL) {
+    return 1;
+  }
+
+  auth_pass = NULL;
+  auth_user = MHD_basic_auth_get_username_password(connection, &auth_pass);
+
+  fail = (auth_user == NULL) || (0 != strcmp(auth_user, "fileshare")) || (0 != strcmp(auth_pass, password));
+
+  if (auth_user != NULL) {
+    free(auth_user);
+  }
+
+  if (auth_pass != NULL) {
+    free(auth_pass);
+  }
+
+  if(fail) {
+    return 0;
+  } else {
+    return 1;
+  }
+}
+
 
 static int connection_handler(void * cls,
     struct MHD_Connection *connection,
@@ -493,6 +525,16 @@ static int connection_handler(void * cls,
       return MHD_queue_response(connection, MHD_HTTP_FORBIDDEN, error403Response);
     }
 
+    // check the authentication, if enabled
+    if(!check_authorization(connection)) {
+      LOG(LVL_WARN,
+          "Unauthorized request from %s for %s .",
+          connstate->clientIP, connstate->localFileName);
+
+      return MHD_queue_basic_auth_fail_response(
+          connection, "Fileshare " VERSION, error401Response);
+    }
+
     // check properties of the target file/dir
     if(stat(connstate->localFileName, &(connstate->targetStat)) == -1) {
       LOG(LVL_ERR, "Cannot stat %s: %s",
@@ -609,13 +651,14 @@ void print_urls(int port) {
   freeifaddrs(ifaddr);
 }
 
-int parse_cmdline(int argc, char **argv, int *port, int *enableUpload, char **shareRoot) {
+int parse_cmdline(int argc, char **argv, int *port, int *enableUpload, char **shareRoot, char **password) {
   int c;
 
   *enableUpload = 0;
   *port = DEFAULT_PORT;
+  *password = NULL;
 
-  while ((c = getopt (argc, argv, "up:")) != -1) {
+  while ((c = getopt (argc, argv, "up:P:")) != -1) {
     switch (c) {
       case 'u':
         *enableUpload = 1;
@@ -632,6 +675,10 @@ int parse_cmdline(int argc, char **argv, int *port, int *enableUpload, char **sh
           return 1;
         }
         break;
+      case 'P':
+        // a password was given on the command line.
+        *password = optarg;
+        break;
       case '?':
         if (optopt == 'p') {
           LOG(LVL_ERR, "Option -%c requires an argument.\n", optopt);
@@ -674,14 +721,15 @@ int main(int argc, char ** argv) {
 #endif
 
   // parse command line arguments
-  if(parse_cmdline(argc, argv, &port, &uploadEnabled, &shareRoot)) {
+  if(parse_cmdline(argc, argv, &port, &uploadEnabled, &shareRoot, &password)) {
     LOG(LVL_ERR, "Failed to parse command line!");
     LOG(LVL_INFO, "Usage: %s [arguments] <dir>", argv[0]);
     LOG(LVL_INFO, "");
     LOG(LVL_INFO, "Arguments:");
     LOG(LVL_INFO, "");
-    LOG(LVL_INFO, "\t-u       Enable Uploads");
-    LOG(LVL_INFO, "\t-p port  Change the listening port.");
+    LOG(LVL_INFO, "\t-u           Enable Uploads");
+    LOG(LVL_INFO, "\t-p port      Change the listening port.");
+    LOG(LVL_INFO, "\t-P password  Optional password for HTTP authentication.");
     LOG(LVL_INFO, "");
     return 1;
   }
@@ -690,6 +738,12 @@ int main(int argc, char ** argv) {
     LOG(LVL_WARN, "Uploads are enabled. Users can create new files anywhere in %s !", shareRoot);
   }
 
+  if(password != NULL) {
+    LOG(LVL_INFO, "HTTP Authentication enabled. Clients must log in as user 'fileshare', password '%s'.", password);
+  } else {
+    LOG(LVL_WARN, "HTTP Authentication disabled, everybody can download the shared files!");
+  }
+
   // check if shareRoot is an existing directory
   if(stat(shareRoot, &sBuf) == -1) {
     LOG(LVL_FATAL, "Cannot stat %s: %s", shareRoot, strerror(errno));
@@ -728,6 +782,12 @@ int main(int argc, char ** argv) {
   init_signal_handlers();
 
   // create the static response for error pages
+  error401Response = MHD_create_response_from_data(
+      strlen(ERROR_401),
+      (void*) ERROR_401,
+      MHD_NO,
+      MHD_NO);
+
   error403Response = MHD_create_response_from_data(
       strlen(ERROR_403),
       (void*) ERROR_403,
@@ -746,6 +806,7 @@ int main(int argc, char ** argv) {
       MHD_NO,
       MHD_NO);
 
+  MHD_add_response_header(error401Response, MHD_HTTP_HEADER_CONTENT_TYPE, "text/html");
   MHD_add_response_header(error403Response, MHD_HTTP_HEADER_CONTENT_TYPE, "text/html");
   MHD_add_response_header(error404Response, MHD_HTTP_HEADER_CONTENT_TYPE, "text/html");
   MHD_add_response_header(error500Response, MHD_HTTP_HEADER_CONTENT_TYPE, "text/html");
@@ -810,6 +871,7 @@ int main(int argc, char ** argv) {
 
   MHD_stop_daemon(d6);
 
+  MHD_destroy_response(error401Response);
   MHD_destroy_response(error403Response);
   MHD_destroy_response(error404Response);
   MHD_destroy_response(error500Response);