public function generateV5($namespace, $salt)
    {
        if (!$this->isValid($namespace)) {
            throw new \Exception('Provided $namespace is invalid: ' . $namespace);
        }

        // Get hexadecimal components of namespace
        $nhex = str_replace(array('-','{','}'), '', $namespace);

        // Binary Value
        $nstr = '';

        // Convert Namespace UUID to bits
        for ($i = 0; $i < strlen($nhex); $i += 2) {
            $nstr .= chr(hexdec($nhex[$i] . $nhex[$i+1]));
        }

        // Calculate hash value
        $hash = sha1($nstr . $salt);

        $guid = sprintf('%08s%04s%04x%04x%12s',
            // 32 bits for "time_low"
            substr($hash, 0, 8),

            // 16 bits for "time_mid"
            substr($hash, 8, 4),

            // 16 bits for "time_hi_and_version",
            // four most significant bits holds version number 3
            (hexdec(substr($hash, 12, 4)) & 0x0fff) | 0x3000,

            // 16 bits, 8 bits for "clk_seq_hi_res",
            // 8 bits for "clk_seq_low",
            // two most significant bits holds zero and one for variant DCE1.1
            (hexdec(substr($hash, 16, 4)) & 0x3fff) | 0x8000,

            // 48 bits for "node"
            substr($hash, 20, 12)
        );

        return $guid;
    }