Management of server keys

I plan to put a SSH server on microcontroller devices. There shall be many devices distributed in a wide range.

The indentity of the server is checked with the server key. The server needs to store the private key to allow the authentication. When I copy the private key to all microcontrollers I have to generate the private key elsewhere (e.g. at my PC). This copy of the private key can be thieved.

It would be more secure when the server generates a key pair and the private key will never be copied from the microcontroller.

• How can I check that I am connected to a server and not to a man in the middle?


• How should I distribute this information to all clients?

The server should work standalone without a hierarchical trust infrastructure?