diff --git a/wp-admin/js/password-strength-meter.js b/wp-admin/js/password-strength-meter.js
index f9f1d5341e..94e7eb145f 100644
--- a/wp-admin/js/password-strength-meter.js
+++ b/wp-admin/js/password-strength-meter.js
@@ -1,79 +1,23 @@
 // Password strength meter
-// This jQuery plugin is written by firas kassem [2007.04.05]
-// Firas Kassem  phiras.wordpress.com || phiras at gmail {dot} com
-// for more information : http://phiras.wordpress.com/2007/04/08/password-strength-meter-a-jquery-plugin/
 
 function passwordStrength(password,username) {
-    var shortPass = 1, badPass = 2, goodPass = 3, strongPass = 4, score = 0, d, s, u, l;
+    var shortPass = 1, badPass = 2, goodPass = 3, strongPass = 4;
 
-    //password < 4
+	//password < 4
     if (password.length < 4 ) { return shortPass };
 
     //password == username
     if (password.toLowerCase()==username.toLowerCase()) return badPass;
 
-    //password length
-    score += password.length * 4;
-    score += ( checkRepetition(1,password).length - password.length ) * 1;
-    score += ( checkRepetition(2,password).length - password.length ) * 1;
-    score += ( checkRepetition(3,password).length - password.length ) * 1;
-    score += ( checkRepetition(4,password).length - password.length ) * 1;
-
-    d = password.match(/\d/g);
-    s = password.match(/[^\d\w]/g);
-    u = password.match(/[A-Z]/g);
-    l = password.match(/[a-z]/g);
-
-	//password has 3 numbers
-    if ( d && d.length > 2 ) score += 5;
-
-    //password has 2 sybols
-    if ( s && s.length > 1 ) score += 10;
-
-    //password has Upper and Lower chars
-    if ( u && l ) score += 10;
-
-    //password has number and chars
-    if ( u && l && d ) score += 15;
-    //
-    //password has number and symbol
-    if ( s && d ) score += 15;
-
-    //password has Upper char and symbol
-    if ( u && s ) score += 15;
-
-    //password is just a nubers or chars
-    if ( ! s )  score -= 10;
-
-    //verifing 0 < score < 100
-    if ( score < 0 )  score = 0;
-    if ( score > 100 )  score = 100;
-
-    if ( score < 34 ) return badPass;
-    if ( score < 68 || password.length < 7 ) return goodPass;
+	var symbolSize = 0;
+	if (password.match(/[0-9]/)) symbolSize +=10;
+	if (password.match(/[a-z]/)) symbolSize +=26;
+	if (password.match(/[A-Z]/)) symbolSize +=26; 
+	if (password.match(/[^a-zA-Z0-9]/)) symbolSize +=31;
+    
+	var natLog = Math.log( Math.pow(symbolSize,password.length) );
+	var score = natLog / Math.LN2;
+	if (score < 40 )  return badPass
+	if (score < 56 )  return goodPass
     return strongPass;
-}
-
-
-// checkRepetition(1,'aaaaaaabcbc')   = 'abcbc'
-// checkRepetition(2,'aaaaaaabcbc')   = 'aabc'
-// checkRepetition(2,'aaaaaaabcdbcd') = 'aabcd'
-
-function checkRepetition(pLen,str) {
-    res = ""
-    for ( i=0; i<str.length ; i++ ) {
-        repeated=true
-        for (j=0;j < pLen && (j+i+pLen) < str.length;j++)
-            repeated=repeated && (str.charAt(j+i)==str.charAt(j+i+pLen))
-        if (j<pLen) repeated=false
-        if (repeated) {
-            i+=pLen-1
-            repeated=false
-        }
-        else {
-            res+=str.charAt(i)
-        }
-    }
-    return res
-}
-
+}
\ No newline at end of file
diff --git a/wp-includes/script-loader.php b/wp-includes/script-loader.php
index e6557cd827..7fe1b6c9d7 100644
--- a/wp-includes/script-loader.php
+++ b/wp-includes/script-loader.php
@@ -147,7 +147,7 @@ function wp_default_scripts( &$scripts ) {
 		$scripts->add( 'admin-categories', '/wp-admin/js/categories.js', array('wp-lists', 'columns', 'settings-box'), '20080925' );
 		$scripts->add( 'admin-tags', '/wp-admin/js/tags.js', array('wp-lists', 'columns', 'settings-box'), '20080925' );
 		$scripts->add( 'admin-custom-fields', '/wp-admin/js/custom-fields.js', array('wp-lists'), '20070823' );
-		$scripts->add( 'password-strength-meter', '/wp-admin/js/password-strength-meter.js', array('jquery'), '20080824' );
+		$scripts->add( 'password-strength-meter', '/wp-admin/js/password-strength-meter.js', array('jquery'), '20081021' );
 		$scripts->localize( 'password-strength-meter', 'pwsL10n', array(
 			'empty' => __('Strength indicator'),
 			'short' => __('Very weak'),