diff --git a/keymgmt.sh b/keymgmt.sh
new file mode 100755
index 0000000..2053662
--- /dev/null
+++ b/keymgmt.sh
@@ -0,0 +1,59 @@
+#!/bin/bash
+
+# key management funcion
+
+interactive()
+{
+
+    tty -s
+    return $?
+
+}
+
+keymgmt()
+{
+
+    local username=$(id -un)
+    local userid=$(id -u)
+
+    #find out where running users $HOME is
+    while read line; do
+        line=$(echo $line | sed 's/ //g')
+        line=$(echo $line | sed 's/:/ /g')
+        if [ $(echo $line | awk '{print $3}') -eq $userid ]; then
+            local home=$(echo $line | awk '{print $6}')
+        fi
+    done < /etc/passwd
+
+    if [ -z $1 ]; then
+        sshkeyfile="$home/.ssh/id_rsa"
+    else
+        sshkeyfile="$1"
+    fi
+
+    if [ -r $sshkeyfile ]; then
+        #ssh key found
+        :
+    else
+        if ( interactive ); then
+            echo "no ssh key found"
+            echo -e "do you want to create a ssh key pair? [y/n] \c"
+            read choice
+            if [ -z $choice ]; then
+                echo "aborting mission. no ssh key found."
+                exit 1
+            elif [ $choice == "y" ] || [ $choice == "Y" ]; then
+                #creating ssh key pair
+                ssh-keygen
+            fi
+        else
+            echo "aborting mission. no ssh key found."
+            exit 1
+        fi
+    fi
+
+}
+
+keymgmt
+
+#end of file
diff --git a/sshbackup b/sshbackup
index 3abdb5d..38e4dc6 100755
--- a/sshbackup
+++ b/sshbackup
@@ -7,7 +7,7 @@
 # ************************************* # 
 
 #  ****  config section  ****
-version="0.3.1"
+version="0.4.0"
 author="david@socialnerds.org"
 
 configfile="$HOME/.sshbackup"
@@ -23,6 +23,7 @@ versions=999
 config=0
 sshkey=0
 list=0
+bandwidth=0
 options=$*
 
 
@@ -51,6 +52,7 @@ usage()
     echo "   -l, --list <file>         list of sources and destinations"
     echo "   -c, --config <file>       alternate config file [~/.sshbackup]"
     echo "   -s, --sshkey <file>       alternate sshkey [~/.ssh/id_rsa]"
+    echo "   -b, --bandwidth <kbps>    bandwidth limit in kbit per second"
     echo
 
 }
@@ -122,6 +124,9 @@ sshbackup()
         cmdopt="$cmdopt --link-dest=$destpath/1"
     fi
 
+    #bandwidth limit
+    if [ 
+
     #run rsync
     $localcmd $cmdopt -e "ssh -q -i $sshkeyfile" --rsync-path="$remotecmd" $sourcepath $destpath/0
     if [ $? -ne "0" ]; then
@@ -170,6 +175,9 @@ for option in $options; do
         -s|--sshkey)
             sshkey=1
             ;;
+        -b|--bandwidth)
+            bandwidth=1
+            ;;
         *)
             if [ $config -eq 1 ]; then
                 if [ -r "$option" ]; then
@@ -187,6 +195,15 @@ for option in $options; do
                     echo "aborting mission. cannot read sshkeyfile. [$option]"
                     exit 1
                 fi
+            elif [ $bandwidth -eq 1 ];then
+                #TODO: better check if its a number (from 1 to gigabit)
+                if [ -z $option ]; then
+                    limit=$option
+                    bandwidth=0
+                else
+                    echo "aborting mission. bandwidth limit not given. [-b $option]"
+                    exit 1
+                fi
             elif [ $list -eq 1 ]; then
                 if [ -r $option ]; then
                     listfile=$option