Can we use ftps directory instead of Physical root directory for Document Sync Server

We are using multi-server environments with Sage CRM 7.1 version and separate document server. Planned to re-platforming environment and upgrade latest version. due to security restrictions we cant use document server within security zone. Currently referring (Physical root directory) shared folder path in Document Sync Server config. Can we use ftps directory instead of shared folder for Document Sync Server ? or can we use http option for document server ? please advise