# Example: Enabling passwordless SSH
<a name="working-with_ec2-user-data_efs_ssh"></a>

You can build on the shared home directory example to implement SSH connections between cluster instances using SSH keys. For each user using the shared home file system, run a script that resembles the following: 

```
#!/bin/bash

mkdir -p $HOME/.ssh && chmod 700 $HOME/.ssh
touch $HOME/.ssh/authorized_keys
chmod 600 $HOME/.ssh/authorized_keys

if [ ! -f "$HOME/.ssh/id_rsa" ]; then
    ssh-keygen -t rsa -b 4096 -f $HOME/.ssh/id_rsa -N ""
    cat ~/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys
fi
```

**Note**  
The instances must use a security group that allows SSH connections between cluster nodes.