A transfer client system exchanges files with a transfer server over an open network such as the Internet. The transfer client comprises an upload directory for storing files for subsequent transfer to the transfer server, an authentication registry securely storing authentication credentials, and a transfer client. The transfer client sends a log-on message to a remote transfer server over a secure transport protocol logical connection established over the open network. The log-on message includes the authentication credentials. In response the transfer client receives a session ID from the remote transfer server. The transfer client then sends a read event message to the remote transfer server which includes Session ID obtained from the remote transfer server. In response the transfer client obtains event parameters which include identification of a file name and an upload directory path previously stored in an events parameter table. The transfer client searches the upload directory and makes a file upload method call included within a Simple Object Access Protocol message over a secure transport layer logical connection over the open network to provide, to the transfer server, the binary contents of a file matching the file name and located in the upload directory.