Deadmann is an online dead man's switch network. Whenever a switch (known as a deadmann node) has not reauthenticated after a set period of time, it expires and an alert message is broadcasted to any deadmann node that communicates with it. Node to node connections have perfect foward secrecy with strong encryption.
All connections to any deadmann node is done over tor. Tor provides deadmann with additional end-to-end encryption along with self validation and anonymity for all nodes. Quite often, no configuration with the network firewall is necessary. The Raspberry Pi 3 makes for a really convenient machine to run a Deadmann node on, as you can have one plugged into a power outlet close enough to a stable wifi internet connection.
Any further details can be found in the README file.