Just the way Richard mentions in his comment to your question, you can use sockets to establish a network connection and send the file over to that machine. Once you have encrypted the message, ping the device and request it to allow your device to send the data. Once the connection has been established, start sending the data. Then, on the other side, receive the data and decrypt it there.
Primarily, it is simpler than it sounds, the only addition is of
TcpListener
and
TcpClient
objects that would both applications to communicate over the network.
I wrote just the article that covers everything you may want to know before proceeding with creation of such applications, that can communicate on the network, have a look at it here,
Creating a server/client application using native .NET TCP library[
^]. Then you can send the data from one machine to another.