Simple Decryption Protector for Number Systems for MySQL Queries

getINForProtectedNumber

/**
 * getINForProtectedNumber()
 *
 * Protects an Number System with an alpha numeric stripper by replace the number of characters to be $protect and replaced
 * with an alpha character from the english characters in capitals for IP Address, Phone Numbers, Addresses!
 *
 * Result for function is used in the following for matching store numbers in a mysql database
 * 
 *  $sql = "SELECT * FROM `cards` WHERE `number` IN ('" . implode("', '", $results['in']) . "')";
 * 
 * @param string    $number     the number string being protected
 * @param integer   $protect    the number of character to replace 1 - 9
 * @return array
 */
function getINForProtectedNumber($number, $protect = 2) {    
{
    $pool = getCollapsingNumberArray(0, 1, $protect, array());
    $results = array('number'=>$number);
    foreach($pool as $number => $lot)
    {
        $key = implode("-", $lot);
        $results['in'][$key] = str_replace($lot, "_", $number);
    }
    return $results;
}

/**
 * getCollapsingNumberArray()
 *
 * Gets a collapsed array with all the numeric changed for an replace for a LIKE/IN with SQL for matching a protected number
 *
 * @param integer   $depth      the depth explored so far
 * @param integer   $level      the number level explored so far
 * @param integer   $protect    the number of character to replace 1 - 9
 * @param array     $results    the array object that is passed in final return
 * @param array     $lot        the number replacement lotto
 * @param string    $key        the array object that is passed into function key indicies
 * @return array
 */
function getCollapsingNumberArray($depth = 0, $level = 1, $protect = 2, $results = array(), $lot = array(), $key ='') {
{
    if (!empty($key) && count($lot)>0)
        $results[$key] = $lot;
    
    if (($depth < $protect && count($lot)<$protect) && $level <= 9)
    {
        $depth++;
        for($ilevel = $level; $ilevel <= 9; $ilevel++) {
            $index = "$key" . (strlen($key)>0?"-":"") . "$ilevel";
            $results = getCollapsingNumberArray($depth, ++$level, $protect, array_merge(array($ilevel), $results, $results[(strlen($key)>0?(isset($results[$key])?$results[$key]:(isset($results[$ilevel]))):array())]), $index);
            $level--;
        }
        $depth--;
    }
    return $results;
}