diff --git a/core/src/conf/bootstrap_context.php b/core/src/conf/bootstrap_context.php
index 422e07f838..9a4eeecae8 100644
--- a/core/src/conf/bootstrap_context.php
+++ b/core/src/conf/bootstrap_context.php
@@ -72,6 +72,24 @@
 define("AJXP_SERVER_DEBUG"  ,	false);
 define("AJXP_SKIP_CACHE"    ,   false);
 
+
+// PBKDF2 CONSTANTS FOR A SECURE STORAGE OF PASSWORDS
+// These constants may be changed without breaking existing hashes.
+define("PBKDF2_HASH_ALGORITHM", "sha256");
+define("PBKDF2_ITERATIONS", 1000);
+define("PBKDF2_SALT_BYTE_SIZE", 24);
+define("PBKDF2_HASH_BYTE_SIZE", 24);
+
+define("HASH_SECTIONS", 4);
+define("HASH_ALGORITHM_INDEX", 0);
+define("HASH_ITERATION_INDEX", 1);
+define("HASH_SALT_INDEX", 2);
+define("HASH_PBKDF2_INDEX", 3);
+
+// CAN BE SWITCHED TO TRUE TO MAKE THE SECURE TOKEN MORE SAFE
+// MAKE SURE YOU HAVE PHP.5.3, OPENSSL, AND THAT IT DOES NOT DEGRADE PERFORMANCES
+define("USE_OPENSSL_RANDOM", false);
+
 require(AJXP_BIN_FOLDER."/compat.php");
 
 function AjaXplorer_autoload($className){
diff --git a/core/src/core/classes/class.AJXP_Utils.php b/core/src/core/classes/class.AJXP_Utils.php
index 5cfa4d190c..f4ffbc7674 100644
--- a/core/src/core/classes/class.AJXP_Utils.php
+++ b/core/src/core/classes/class.AJXP_Utils.php
@@ -24,6 +24,27 @@
 define('AJXP_SANITIZE_HTML_STRICT', 2);
 define('AJXP_SANITIZE_ALPHANUM', 3);
 define('AJXP_SANITIZE_EMAILCHARS', 4);
+
+// THESE ARE DEFINED IN bootstrap_context.php
+// REPEAT HERE FOR BACKWARD COMPATIBILITY.
+if(!defined('PBKDF2_HASH_ALGORITHM')){
+
+    define("PBKDF2_HASH_ALGORITHM", "sha256");
+    define("PBKDF2_ITERATIONS", 1000);
+    define("PBKDF2_SALT_BYTE_SIZE", 24);
+    define("PBKDF2_HASH_BYTE_SIZE", 24);
+
+    define("HASH_SECTIONS", 4);
+    define("HASH_ALGORITHM_INDEX", 0);
+    define("HASH_ITERATION_INDEX", 1);
+    define("HASH_SALT_INDEX", 2);
+    define("HASH_PBKDF2_INDEX", 3);
+
+    define("USE_OPENSSL_RANDOM", false);
+
+}
+
+
 /**
  * Various functions used everywhere, static library
  * @package AjaXplorer
@@ -1603,4 +1624,131 @@ public static function runCreateTablesQuery($p, $file){
 
     }
 
+
+    /*
+     * PBKDF2 key derivation function as defined by RSA's PKCS #5: https://www.ietf.org/rfc/rfc2898.txt
+     * $algorithm - The hash algorithm to use. Recommended: SHA256
+     * $password - The password.
+     * $salt - A salt that is unique to the password.
+     * $count - Iteration count. Higher is better, but slower. Recommended: At least 1000.
+     * $key_length - The length of the derived key in bytes.
+     * $raw_output - If true, the key is returned in raw binary format. Hex encoded otherwise.
+     * Returns: A $key_length-byte key derived from the password and salt.
+     *
+     * Test vectors can be found here: https://www.ietf.org/rfc/rfc6070.txt
+     *
+     * This implementation of PBKDF2 was originally created by https://defuse.ca
+     * With improvements by http://www.variations-of-shadow.com
+     */
+    static function pbkdf2_apply($algorithm, $password, $salt, $count, $key_length, $raw_output = false) {
+
+        $algorithm = strtolower($algorithm);
+
+        if(!in_array($algorithm, hash_algos(), true))
+            die('PBKDF2 ERROR: Invalid hash algorithm.');
+        if($count <= 0 || $key_length <= 0)
+            die('PBKDF2 ERROR: Invalid parameters.');
+
+        $hash_length = strlen(hash($algorithm, "", true));
+        $block_count = ceil($key_length / $hash_length);
+
+        $output = "";
+
+        for($i = 1; $i <= $block_count; $i++) {
+            // $i encoded as 4 bytes, big endian.
+            $last = $salt . pack("N", $i);
+            // first iteration
+            $last = $xorsum = hash_hmac($algorithm, $last, $password, true);
+
+            // perform the other $count - 1 iterations
+            for ($j = 1; $j < $count; $j++) {
+                $xorsum ^= ($last = hash_hmac($algorithm, $last, $password, true));
+            }
+
+            $output .= $xorsum;
+        }
+
+        if($raw_output)
+            return substr($output, 0, $key_length);
+        else
+            return bin2hex(substr($output, 0, $key_length));
+    }
+
+
+    // Compares two strings $a and $b in length-constant time.
+    static function pbkdf2_slow_equals($a, $b) {
+        $diff = strlen($a) ^ strlen($b);
+        for($i = 0; $i < strlen($a) && $i < strlen($b); $i++)
+        {
+            $diff |= ord($a[$i]) ^ ord($b[$i]);
+        }
+
+        return $diff === 0;
+    }
+
+    static function pbkdf2_validate_password($password, $correct_hash) {
+        $params = explode(":", $correct_hash);
+
+        if(count($params) < HASH_SECTIONS){
+            if(strlen($correct_hash) == 32 && count($params) == 1){
+                return md5($password) == $correct_hash;
+            }
+            return false;
+        }
+
+        $pbkdf2 = base64_decode($params[HASH_PBKDF2_INDEX]);
+        return self::pbkdf2_slow_equals(
+            $pbkdf2,
+             self::pbkdf2_apply(
+                $params[HASH_ALGORITHM_INDEX],
+                $password,
+                $params[HASH_SALT_INDEX],
+                (int)$params[HASH_ITERATION_INDEX],
+                strlen($pbkdf2),
+                true
+            )
+        );
+    }
+
+
+    static function pbkdf2_create_hash($password) {
+        // format: algorithm:iterations:salt:hash
+        $salt = base64_encode(mcrypt_create_iv(PBKDF2_SALT_BYTE_SIZE, MCRYPT_DEV_URANDOM));
+        return PBKDF2_HASH_ALGORITHM . ":" . PBKDF2_ITERATIONS . ":" .  $salt . ":" .
+        base64_encode(self::pbkdf2_apply(
+            PBKDF2_HASH_ALGORITHM,
+            $password,
+            $salt,
+            PBKDF2_ITERATIONS,
+            PBKDF2_HASH_BYTE_SIZE,
+            true
+        ));
+    }
+
+    /**
+     * generates a random password, uses base64: 0-9a-zA-Z
+     * @param int [optional] $length length of password, default 24 (144 Bit)
+     * @return string password
+     */
+    static function generateRandomString($length = 24) {
+        if(function_exists('openssl_random_pseudo_bytes') && USE_OPENSSL_RANDOM) {
+            $password = base64_encode(openssl_random_pseudo_bytes($length, $strong));
+            if($strong == TRUE)
+                return substr(str_replace(array("/","+"), "", $password), 0, $length); //base64 is about 33% longer, so we need to truncate the result
+        }
+
+        //fallback to mt_rand if php < 5.3 or no openssl available
+        $characters = '0123456789';
+        $characters .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
+        $charactersLength = strlen($characters)-1;
+        $password = '';
+
+        //select some random characters
+        for ($i = 0; $i < $length; $i++) {
+            $password .= $characters[mt_rand(0, $charactersLength)];
+        }
+
+        return $password;
+    }
+
 }
\ No newline at end of file
diff --git a/core/src/core/classes/class.AuthService.php b/core/src/core/classes/class.AuthService.php
index c1f29f5834..e798c98e4c 100644
--- a/core/src/core/classes/class.AuthService.php
+++ b/core/src/core/classes/class.AuthService.php
@@ -65,7 +65,8 @@ static function generateSeed(){
      * @return
      */
 	static function generateSecureToken(){
-		$_SESSION["SECURE_TOKEN"] = md5(time());
+
+		$_SESSION["SECURE_TOKEN"] = AJXP_Utils::generateRandomString(32); //md5(time());
 		return $_SESSION["SECURE_TOKEN"];
 	}
 	/**
@@ -212,7 +213,7 @@ static function refreshRememberCookie($user){
             $user->invalidateCookieString(substr($current, strpos($current, ":")+1));
         }
         $rememberPass = $user->getCookieString();
-        setcookie("AjaXplorer-remember", $user->id.":".$rememberPass, time()+3600*24*10);
+        setcookie("AjaXplorer-remember", $user->id.":".$rememberPass, time()+3600*24*10, null, null, (isSet($_SERVER["HTTPS"]) && strtolower($_SERVER["HTTPS"]) == "on"), true);
     }
 
     /**
@@ -233,7 +234,7 @@ static function clearRememberCookie(){
         if(!empty($current) && $user != null){
             $user->invalidateCookieString(substr($current, strpos($current, ":")+1));
         }
-        setcookie("AjaXplorer-remember", "", time()-3600);
+        setcookie("AjaXplorer-remember", "", time()-3600, null, null, (isSet($_SERVER["HTTPS"]) && strtolower($_SERVER["HTTPS"]) == "on"), true);
     }
 
     static function logTemporaryUser($parentUserId, $temporaryUserId){
diff --git a/core/src/plugins/auth.remote/class.remoteAuthDriver.php b/core/src/plugins/auth.remote/class.remoteAuthDriver.php
index 34e2f7014d..9278a17658 100644
--- a/core/src/plugins/auth.remote/class.remoteAuthDriver.php
+++ b/core/src/plugins/auth.remote/class.remoteAuthDriver.php
@@ -132,7 +132,7 @@ function checkPassword($login, $pass, $seed){
 			$userStoredPass = $this->getUserPass($login);
 			if(!$userStoredPass) return false;
 			if($seed == "-1"){ // Seed = -1 means that password is not encoded.
-				return ($userStoredPass == md5($pass));
+				return  AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass);// ($userStoredPass == md5($pass));
 			}else{
 				return (md5($userStoredPass.$seed) == $pass);
 			}			
@@ -164,7 +164,7 @@ function checkPassword($login, $pass, $seed){
             $userStoredPass = $this->getUserPass($login);
             if(!$userStoredPass) return false;
             if($seed == "-1"){ // Seed = -1 means that password is not encoded.
-                $res = ($userStoredPass == md5($pass));
+                $res = AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass); //($userStoredPass == md5($pass));
             }else{
                 $res = (md5($userStoredPass.$seed) == $pass);
             }
@@ -195,7 +195,7 @@ function createUser($login, $passwd){
 		if(!is_array($users)) $users = array();
 		if(array_key_exists($login, $users)) return "exists";
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$users[$login] = md5($passwd);
+			$users[$login] = AJXP_Utils::pbkdf2_create_hash($passwd);
 		}else{
 			$users[$login] = $passwd;
 		}
@@ -206,7 +206,7 @@ function changePassword($login, $newPass){
 		$users = $this->listUsers();
 		if(!is_array($users) || !array_key_exists($login, $users)) return ;
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$users[$login] = md5($newPass);
+			$users[$login] = AJXP_Utils::pbkdf2_create_hash($newPass);
 		}else{
 			$users[$login] = $newPass;
 		}
diff --git a/core/src/plugins/auth.serial/class.serialAuthDriver.php b/core/src/plugins/auth.serial/class.serialAuthDriver.php
index f0f7b7abad..5c0a81d225 100644
--- a/core/src/plugins/auth.serial/class.serialAuthDriver.php
+++ b/core/src/plugins/auth.serial/class.serialAuthDriver.php
@@ -106,7 +106,7 @@ function checkPassword($login, $pass, $seed){
 		$userStoredPass = $this->getUserPass($login);
 		if(!$userStoredPass) return false;
 		if($seed == "-1"){ // Seed = -1 means that password is not encoded.
-			return ($userStoredPass == md5($pass));
+			return AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass);//($userStoredPass == md5($pass));
 		}else{
 			return (md5($userStoredPass.$seed) == $pass);
 		}
@@ -125,7 +125,7 @@ function createUser($login, $passwd){
 		if(!is_array($users)) $users = array();
 		if(array_key_exists($login, $users)) return "exists";
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$users[$login] = md5($passwd);
+			$users[$login] = AJXP_Utils::pbkdf2_create_hash($passwd);//md5($passwd);
 		}else{
 			$users[$login] = $passwd;
 		}
@@ -136,7 +136,7 @@ function changePassword($login, $newPass){
 		$users = $this->_listAllUsers();
 		if(!is_array($users) || !array_key_exists($login, $users)) return ;
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$users[$login] = md5($newPass);
+			$users[$login] = AJXP_Utils::pbkdf2_create_hash($newPass);//md5($newPass);
 		}else{
 			$users[$login] = $newPass;
 		}
diff --git a/core/src/plugins/auth.serial_otp/class.serial_otpAuthDriver.php b/core/src/plugins/auth.serial_otp/class.serial_otpAuthDriver.php
index fa303073a9..55f3a7214e 100644
--- a/core/src/plugins/auth.serial_otp/class.serial_otpAuthDriver.php
+++ b/core/src/plugins/auth.serial_otp/class.serial_otpAuthDriver.php
@@ -133,7 +133,7 @@ function checkPassword($login, $pass, $seed){
 
 		//No OTP token is set
 		if ($g == '' and $y1 == '' and $y2 == ''){
-			return ($userStoredPass == md5($pass));
+			return AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass); //($userStoredPass == md5($pass));
 		}
 
 		//Just the Google Authenticator set
@@ -171,7 +171,7 @@ function createUser($login, $passwd){
 		if(!is_array($users)) $users = array();
 		if(array_key_exists($login, $users)) return "exists";
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$users[$login] = md5($passwd);
+			$users[$login] = AJXP_Utils::pbkdf2_create_hash($passwd);
 		}else{
 			$users[$login] = $passwd;
 		}
@@ -183,7 +183,7 @@ function changePassword($login, $newPass){
 		$users = $this->_listAllUsers();
 		if(!is_array($users) || !array_key_exists($login, $users)) return ;
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$users[$login] = md5($newPass);
+			$users[$login] = AJXP_Utils::pbkdf2_create_hash($newPass);
 		}else{
 			$users[$login] = $newPass;
 		}
@@ -314,7 +314,7 @@ function checkGooglePass($login, $pass, $userStoredPass, $userToken, $userInvali
 			}
 		}
 
-		return ($userStoredPass == md5($pass) && $valid == 1);
+		return ( AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass) && $valid == 1);
 	}
 
 
@@ -336,7 +336,7 @@ function checkYubiPass($pass, $userStoredPass, $yubikey1, $yubikey2) {
 		$yubi = new Auth_Yubico($this->yubico_client_id, $this->yubico_secret_key);
 		$auth = $yubi->verify($yotp);
 
-		return ((!PEAR::isError($auth)) && $userStoredPass == md5($pass));
+		return ((!PEAR::isError($auth)) &&  AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass));
 	}
 }
 ?>
diff --git a/core/src/plugins/auth.sql/class.sqlAuthDriver.php b/core/src/plugins/auth.sql/class.sqlAuthDriver.php
index fabb0bd6c8..6861d3c4a6 100644
--- a/core/src/plugins/auth.sql/class.sqlAuthDriver.php
+++ b/core/src/plugins/auth.sql/class.sqlAuthDriver.php
@@ -99,7 +99,7 @@ function checkPassword($login, $pass, $seed){
 		if(!$userStoredPass) return false;		
 		
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){ // Seed = -1 means that password is not encoded.
-			return ($userStoredPass == md5($pass));
+			return AJXP_Utils::pbkdf2_validate_password($pass, $userStoredPass); //($userStoredPass == md5($pass));
 		}else{
 			return (md5($userStoredPass.$seed) == $pass);
 		}
@@ -116,7 +116,7 @@ function createUser($login, $passwd){
 		if($this->userExists($login)) return "exists";
 		$userData = array("login" => $login);
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$userData["password"] = md5($passwd);
+			$userData["password"] = AJXP_Utils::pbkdf2_create_hash($passwd); //md5($passwd);
 		}else{
 			$userData["password"] = $passwd;
 		}
@@ -127,7 +127,7 @@ function changePassword($login, $newPass){
         if(!$this->userExists($login)) throw new Exception("User does not exists!");
 		$userData = array("login" => $login);
 		if($this->getOption("TRANSMIT_CLEAR_PASS") === true){
-			$userData["password"] = md5($newPass);
+			$userData["password"] = AJXP_Utils::pbkdf2_create_hash($newPass); //md5($newPass);
 		}else{
 			$userData["password"] = $newPass;
 		}
diff --git a/core/src/plugins/core.conf/class.AbstractAjxpUser.php b/core/src/plugins/core.conf/class.AbstractAjxpUser.php
index 2805b03dd4..dffaed5fae 100644
--- a/core/src/plugins/core.conf/class.AbstractAjxpUser.php
+++ b/core/src/plugins/core.conf/class.AbstractAjxpUser.php
@@ -95,11 +95,11 @@ function getCookieString(){
         }else{
             $hashes = explode(",", $hashes);
         }
-        $newHash =  md5($this->id.":".time());
+        $newHash = md5($this->id.":".AJXP_Utils::generateRandomString());
         array_push($hashes, $newHash);
         $this->setPref("cookie_hash", implode(",",$hashes));
         $this->save("user");
-		return $newHash; //md5($this->id.":".$newHash.":ajxp");
+		return $newHash;
 	}
 	
 	function getId(){