This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
One can install a sniffer in the network between the both machines and read all sent/received bytes. In for example a proxy, firewall, router or even your own machine. SSL encrypts those bytes before sending and decrypts them before reading.