Method and system for selecting a communication interface

A method for managing group files, comprising:

• selecting a default access control list or creating an access control list with respect to a work project;
• acquiring a certificate corresponding to the access control list from a server-side management system;
• establishing one or more policy groups associated to the access control list, wherein each policy group has one or more members;
• wherein the member is subordinate to one or more policy groups, every member obtaining the certificate from the server-side management system and synchronously retrieving one or more group privilege data associated to the subordinate policy groups according to the certificate;
• and every member obtaining one or more access privileges of the files with respect to one or more policy groups according to the group privilege data;
• and
• each policy group beginning to operate, every member is allowing to read, write, print, copy, delete, and convert a file subordinate to the access control list according to the group privilege data.