Here is to PHP lovers, now let us assume you are building a bank portal and you have created your numbers database and you now wish to generate unique 10 digits NUBAN or 11 digits BVN for your customers, here is a simple way to convert a simple digit like 1 into a unique collision-free 10 digit sequence:

<?php
$id=1; //this is the autoincremented id of the customer

//10 digits nuban number
$nuban = strrev(substr((int)($id/5 * 10).rand(pow(10,10), pow(10,11) - 1),0,10));

//11 digits bvn number
$bvn = strrev(substr((int)($id/5 * 10).rand(pow(10,10), pow(10,11) - 1),0,11));

//results
echo 'Your NUBAN is $nuban, and your bvn is '.$bvn;
?>

Disclaimer: please note that this is just a trollin' sample, and no actual BVNs/NUBANS were generated at anytime by disclaimer. And no bank customer was defrauded at any time by this code.