Security

How do you keep an unauthorized node from signing onto your node, or sending and receiving data both to and from your node?
How can you protect the data as it travels through the network?
Does the data require SSL/TLS encryption?
Is there agreement on the use of nodal passwords?
When and how will the passwords be changed?
What kind of protection will the passwords have?
What command authority should participating nodes have on the individual installations?
Should that authority be changed by operator commands?