db4o allows to customize client-server communication by using pluggable socket implementations:
.NET:
public static
IObjectServer OpenServer(IConfiguration config, string databaseFileName, int port, INativeSocketFactory
socketFactory)
public static
IObjectContainer OpenClient(IConfiguration config, string hostName, int port, string user, string
password, INativeSocketFactory socketFactory)
Here NativeSocketFactory interface should be used to provide client and server sockets, which may implement any custom way of communication.
An example of such customary implementation can be encrypted communication.
Note, that this API is in the development stage and is subject to future changes.