PHP加密解密数字

 <?php
 /**
  * 加密解密类,PHP加密解密数字，适用于URL加密
  * 该算法仅支持加密数字。比较适用于数据库中id字段的加密解密，以及根据数字显示url的加密。
  * @version alpha
  * @加密原则 标记长度 + 补位 + 数字替换
  * @加密步骤：
  * 将a-z,A-Z,0-9 62个字符打乱，取前M(数字最大的位数)位作为 标记长度字符串，取第M+1 到第M+10位为数字替换字符串，剩余的为补位字符串
  * 1.计算数字长度n,取乱码的第n位作为标记长度。
  * 2.计算补位的长度，加密串的长度N -1 - n 为补位的长度。根据指定的算法得到补位字符串。
  * 3.根据数字替换字符串替换数字，得到数字加密字符串。
  * 标记长度字符 + 补位字符串 + 数字加密字符串 = 加密串
  * Usage:
  *      $obj = new XDeode(9);
  *      $e_txt = $obj->encode(123);
  *      echo $e_txt.'<br/>';
  *      echo $key->decode($e_txt);
  */
 class XDeode
 {
     private $strbase = "Flpvf70CsakVjqgeWUPXQxSyJizmNH6B1u3b8cAEKwTd54nRtZOMDhoG2YLrI";
     private $key,$length,$codelen,$codenums,$codeext;
     function __construct($length = 9,$key = 2543.5415412812){
         $this->key = $key;
         $this->length = $length;
         $this->codelen = substr($this->strbase,0,$this->length);
         $this->codenums = substr($this->strbase,$this->length,10);
         $this->codeext = substr($this->strbase,$this->length + 10);
     }

     function encode($nums){
         $rtn = "";
         $numslen = strlen($nums);
         //密文第一位标记数字的长度
         $begin = substr($this->codelen,$numslen - 1,1);

         //密文的扩展位
         $extlen = $this->length - $numslen - 1;
         $temp = str_replace('.', '', $nums / $this->key);
         $temp = substr($temp,-$extlen);

         $arrextTemp = str_split($this->codeext);
         $arrext = str_split($temp);
         foreach ($arrext as $v) {
             $rtn .= $arrextTemp[$v];
         }

         $arrnumsTemp = str_split($this->codenums);
         $arrnums = str_split($nums);
         foreach ($arrnums as $v) {
             $rtn .= $arrnumsTemp[$v];
         }
         return $begin.$rtn;
     }

     function decode($code){

         $begin = substr($code,0,1);
         $rtn = '';
         $len = strpos($this->codelen,$begin);
         if($len!== false){
             $len++;
             $arrnums = str_split(substr($code,-$len));
             foreach ($arrnums as $v) {
                 $rtn .= strpos($this->codenums,$v);
             }
         }

         return $rtn;
     }
 }

 $obj = new XDeode(10);
 echo $obj->encode(1)."<br/>";
 echo $obj->encode(2)."<br/>";
 echo $obj->encode(3)."<br/>";
 echo $obj->encode(4)."<br/>";
 echo $obj->encode(5)."<br/>";
 echo $obj->encode(6)."<br/>";
 echo $obj->encode(7)."<br/>";
 echo $obj->encode(8)."<br/>";
 echo $obj->encode(9)."<br/>";
 echo $obj->encode(10)."<br/>";
 echo $obj->encode(45762454)."<br/>";
 echo $obj->encode(1023213123)."<br/>";
 echo $obj->encode(134320)."<br/>";
 echo '<hr/>';

 echo $obj->decode('FzxxmyQzxV')."<br/>";
 echo $obj->decode('FSSyJzxSSj')."<br/>";
 echo $obj->decode('FmNyixHxNq')."<br/>";
 echo $obj->decode('FQJJzHSSJg')."<br/>";
 echo $obj->decode('FzyQiNziye')."<br/>";
 echo $obj->decode('FizmQyNyzW')."<br/>";
 echo $obj->decode('FNSNSxxJyU')."<br/>";
 echo $obj->decode('FQNHyNJJHP')."<br/>";
 echo $obj->decode('FyiQiimiiX')."<br/>";
 echo $obj->decode('lxxmyQzxVk')."<br/>";
 echo $obj->decode('CSgeUWjgeg')."<br/>";
 echo $obj->decode('aQSSmNHxxzzJJNVkjqjVqVjq')."<br/>";
 echo $obj->decode('7ziiVqgqjk')."<br/>";

 //FzxxmyQzxV
 //FSSyJzxSSj
 //FmNyixHxNq
 //FQJJzHSSJg
 //FzyQiNziye
 //FizmQyNyzW
 //FNSNSxxJyU
 //FQNHyNJJHP
 //FyiQiimiiX
 //lxxmyQzxVk
 //CSgeUWjgeg
 //aQSSmNHxxzzJJNVkjqjVqVjq
 //7ziiVqgqjk
 //1
 //2
 //3
 //4
 //5
 //6
 //7
 //8
 //9
 //10
 //45762454
 //1023213123
 //134320