You may wish to allow multiple devices root access to your machine's server.
To add a user with fewer permissions (e.g., no access to bitcoind), follow this article.
Create a new SSH key
For Android devices, JuiceSSH is free app for generating SSH keys and console access.
Copy the public key
Copy the Public Key generated from PuTTY (Windows) or Mac/Linux with the command:
Transfer this key to your computer that currently has access to your Lamassu server. (It's safe to email or otherwise distribute.)
Add to authorized_keys file
Log into your Lamassu server, and run the following command, replacing [publicSSHkey] with the one generated on the device you wish to grant access.
echo -e "\r\n[publicSSHkey]" >> ~/.ssh/authorized_keys
Example: If your public key is:
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCm/Cv/kgU7Ot+OR/Dll4+fAC+lFR0rHC1tFgquMiozgfPFv44jMHe/A/2mvt5zljXQrbH/k4zfQFYAehRzqswXyBheR+6X02q5taFRDm7GKyCGOng2QCbhn/SSm4AeeIIGcNXZZhEo87mm/8VH5nrql3NPQqXs4PIz8HL1bfKHR6VKpcessubKJFYzFOjY5ckgvOvGWjIwvjxnCk24M4UpURWXvAQvAEENox0tsbYdqjabjkLC0TofKvQFU0p0pRT8y3JsGezNQDIhTyNGPcsSmC5KrIBORCi2Gzp5/PY+ftl3jZnNnS5oAhuQ3RyFO6HHphj7WS70D1Q0szRmbju9 email@example.com
Then the command to add it to your server will be:
echo -e "\r\nssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCm/Cv/kgU7Ot+OR/Dll4+fAC+lFR0rHC1tFgquMiozgfPFv44jMHe/A/2mvt5zljXQrbH/k4zfQFYAehRzqswXyBheR+6X02q5taFRDm7GKyCGOng2QCbhn/SSm4AeeIIGcNXZZhEo87mm/8VH5nrql3NPQqXs4PIz8HL1bfKHR6VKpcessubKJFYzFOjY5ckgvOvGWjIwvjxnCk24M4UpURWXvAQvAEENox0tsbYdqjabjkLC0TofKvQFU0p0pRT8y3JsGezNQDIhTyNGPcsSmC5KrIBORCi2Gzp5/PY+ftl3jZnNnS5oAhuQ3RyFO6HHphj7WS70D1Q0szRmbju9 firstname.lastname@example.org" >> ~/.ssh/authorized_keys
Your additional device will now have access to your server and all root permissions, including resetting your admin's password or sending from your bitcoind wallet. Keep the new device's private key as securely as you would your primary key.