From Socket to stream to XML DOM Document

My multi-platform C++ application reads XML in the form of a byte stream from a TCP/IP socket and stores the data in an stl stream. Once all data is read, it then passes the stream to the DOMBuilder which returns a DOMDocument.

I really would like to do this asynchronously to conserve memory and increase performance. I tried to find resources on the net to no avail. Has anybody here some clever ideas?

Another thing that bugs me with XML is the ridiculously huge data size. Is there a common technique used to encrypt/compress and decompress/decrypt XML?