use Illuminate\Support\Facades\Crypt;

echo Crypt::encrypt(123);  //加密
echo "<br>";
//解密
echo Crypt::decrypt("eyJpdiI6InpCcGdBK0JQajJ3c01wSVh2QVVPWmc9PSIsInZhbHVlIjoic3JRSXVTSUpIUTZER0ZVazVKV0t0QT09IiwibWFjIjoiZDllMzFlMzI1NDlhNWVjYzBkMmI0M2FkYzUzZmZjZjI0NThlMmY3NWVlNTc2YzYyNmZlMjMzMmI1ZjMzYTZlNCJ9");

//PHP form 表单认证
后端：

$input=$request->all();
$rules=[
    'username'=>"required|unique:User|between:6,12",   //required是否为空 unique是否存在  between 长度
    "passwd"=>"required|between:6,12|same:repasswd"    //same 是否和repasswd密码一样
];
$message=array(
  "username.required"=>"请输入用户名",
    "username.unique"=>"用户名已存在",
    "username.between"=>"用户名长度不满足",
    "passwd.required"=>"请输密码",
    "passwd.between"=>"用户名长度不满足",
　　 "passwd.same"=>"密码不一样",

);
$validator = \Validator::make($input,$rules,$message);

if($validator->passes()){
        echo 123;

}else{
   return back()->withInput()->withErrors($validator);

前端：

@if(count($errors) >0)

    <div>
        @foreach($errors->all() as $error)
            <li>{{$error}}</li>
        @endforeach
    </div>

@endif

//php  laravel分页  两种分页  第一种比较好

$aa=DB::table("User")->orderBy("id","desc")->paginate(3); 

$aa=DB::table("User")->orderBy("id","desc")->simplePaginate(3);