Securing Raspberry Pi (SSH keys, firewall) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main benefit of using SSH keys instead of passwords for Raspberry Pi access?

SSH keys provide stronger security by using cryptographic keys instead of passwords, making it much harder for attackers to guess or brute-force access.

beginner

How do you generate an SSH key pair on your local computer?

Use the command ssh-keygen in the terminal. This creates a private key (keep secret) and a public key (share with Raspberry Pi).

beginner

What is the purpose of a firewall on a Raspberry Pi?

A firewall controls which network connections are allowed or blocked, protecting the Raspberry Pi from unwanted access or attacks.

intermediate

Which command can you use to enable the firewall on Raspberry Pi running Linux?

You can use sudo ufw enable to turn on the uncomplicated firewall (UFW) on Raspberry Pi.

intermediate

How do you add your public SSH key to the Raspberry Pi to allow key-based login?

Copy your public key to the Raspberry Pi's ~/.ssh/authorized_keys file, for example using ssh-copy-id user@raspberrypi.

What file on the Raspberry Pi stores the list of allowed SSH public keys?

A /etc/ssh/ssh_config

B ~/.ssh/authorized_keys

C ~/.ssh/id_rsa

D /etc/passwd

The file ~/.ssh/authorized_keys contains the public keys allowed for SSH login.

Which command disables password login for SSH on Raspberry Pi?

A ssh-keygen -p

B sudo ufw disable

C sudo systemctl stop ssh

D Edit /etc/ssh/sshd_config and set PasswordAuthentication no

Disabling password login requires editing /etc/ssh/sshd_config and setting PasswordAuthentication no.

What does the command sudo ufw allow 22 do?

A Disables the firewall

B Blocks SSH connections

C Allows SSH connections through the firewall

D Enables the firewall

Port 22 is the default SSH port; this command allows SSH traffic through the firewall.

Why is it important to keep your private SSH key secure?

A Because anyone with it can access your Raspberry Pi

B Because it contains your password

C Because it is stored on the Raspberry Pi

D Because it expires quickly

The private key grants access; if stolen, attackers can log in without a password.

Which tool is commonly used as a simple firewall on Raspberry Pi?

A UFW (Uncomplicated Firewall)

B iptables

C fail2ban

D Wireshark

UFW is a user-friendly firewall tool often used on Raspberry Pi.

Explain how to set up SSH key authentication on a Raspberry Pi.

Think about creating keys, sharing the public one, and securing the server.

Describe the role of a firewall on a Raspberry Pi and how to enable it.

Consider how a firewall protects and how to control access.