How can I create a unique random string in laravel 5

I am new to laravel 5. I am working on a project where I want to assign some random-readable unique string to each application. I have knowledge of the each application id which may be use as a seed. Since the app is going to be use within the company I don't worry much about security. I expect the table size to grow so my goal is to achieve uniqueness as much as possible because the field in DB is unique. A code like (EN1A20, EN12ZOV etc). If the function can allow me to pass the length of the string I want to return, that would be really awesome.

Edit Shown below is my attempt to the problem

private function generate_app_code($application_id) { 
        $token = $this->getToken(6, $application_id);
        $code = 'EN'. $token . substr(strftime("%Y", time()),2);

        return $code;
    }

    private function getToken($length, $seed){    
        $token = "";
        $codeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        $codeAlphabet.= "0123456789";

        mt_srand($seed);      // Call once. Good since $application_id is unique.

        for($i=0;$i<$length;$i++){
            $token .= $codeAlphabet[mt_rand(0,strlen($codeAlphabet)-1)];
        }
        return $token;
    }

Can the code above do the trick?

Appreciate help.

via Chebli Mohamed