Need to create ZIp file with password protect

[maxmathan]

hi,

 

In php,I Need to create ZIp file with password protect.

 

I created like below.

 

$zip = new ZipArchive;

$filename = 'hello.zip';

$res = $zip->open($filename, ZipArchive::CREATE);

 

How to set "passowrdprotect" for hello.zip in PHP code itself?