Smart Home but Secure – Tips for a Trusted Smart Home

Smart Home, Big Brother is watching you?

No. A secure smart home is not a glass box, but an everyday upgrade.

How to do it safely …

Let’s get started!

What is a secure smart home?

Smart home / home automation is a trend that has emerged in recent years, which attempts to digitise and centralise more and more devices in our homes. Sensors and actuators should work in harmony and the system should be optimally protected against criminals.

We have had dumb electronic devices in our homes for a long time. Ever since the first power lines were laid in our homes, we have been able to operate electrical devices. These devices usually require manual interaction (e.g. switching on a light switch by hand). This is where a smart home comes in and attempts to control all devices. Control takes place according to schedules, times of day, events (garage door opens) or as desired via the smartphone. Criminals can intervene in the smart home at various points to gain access to the rooms.

Advantages and risks of networked devices

• Hacker attacks and data breaches: Hackers are not only hacking doors and locks in Hollywood, but CVEs (see Exploits explanation) show us every day that smart door locks and the like are just as insecure as analogue locks. In addition, we pass on data to companies that exploit it for their own purposes.
• Insecure devices and software vulnerabilities: First and foremost, smart home devices are supposed to be cheap and do a lot. Most people don’t care (or don’t realise) whether the manufacturer will still be around in two years’ time. The software is ageing and more and more vulnerabilities against the device are becoming known.

• Manipulation by third parties (e.g. smart locks, cameras): In a home, you should feel safe and not have to think about someone taking over your appliances via the internet. If the shutters open and close in an endless loop and the heating bangs at 50 degrees, criminals will be laughing their heads off.
• Risks from voice assistants and data transfer: Thanks to digital assistants, we can perform many tasks using only our voice. The past has shown that the GDPR is more of a concept than a law for companies.

Choice and responsible use

With smart homes, it all starts with the purchase of devices:

Buying trusted brands and certified devices

Brands are no guarantee for secure devices, but an update guarantee gets us further. If a device is supported for more than 3 years, we can consider ourselves lucky. However, the devices physically function for 20 – 30 years, e.g. roller shutter motor. If you don’t want to change the devices every few years, you either have to take out a maintenance contract or leave the smart home alone.

Minimising cloud dependency and local control

The internet is everything and nothing. If you can no longer open your front door because the radio tower around the corner has the sniffles, you should think about moving away from the cloud. The internal network with access points (WLAN) is capable of performing these tasks on its own, if only the manufacturers want it to.

Rights and access control for users and devices

Not every idiot with a smartphone should be able to open your roller shutters at 4 o’clock in the morning. That’s why it makes sense to activate access blocks and use secure passwords. The first step is to assign a good Wi-Fi password and then securely encrypt the devices. Restrictions below the residents may make sense.

Privacy-friendly alternatives (e.g. open source solutions)

Many smart home devices have their own software solution. The manufacturer wants to make it easy for customers to get started. However, the aspect of data protection often falls by the wayside. The manufacturers do not provide the option of operating the devices locally on the network with open source software. Nevertheless, there are some devices that use open standards and are data-efficient.

The basics of smart home security

Secure passwords and two-factor authentication

Every device and every application needs secure passwords. These must have 12 characters, not be in a dictionary and not have been leaked before. The devices are usually delivered with the same password and customers are not informed (or forced) to change the password.

Regular updates and patch management

Smart home devices are ultraslim and built with minimal hardware requirements. If a software update is too large for the hardware, then the update can no longer be installed. As a rule, most devices do not receive updates because they work straight from the factory. Criminals can exploit the outdated software if the customer does not actively patch or the manufacturer does not roll out patches to all devices.

Network security (router, firewall, VLANs)

Here are some simple tips for network security, especially for routers, firewalls and VLANs:

Router security

1. Change default passwords – Change the default password for router access immediately.
2. Keep firmware up to date – Regular updates close security gaps.
3. Deactivate remote access – If not required, the router should not be accessible from the internet.
4. Use strong Wi-Fi encryption – Use WPA3 or at least WPA2-PSK with a strong password.
5. Enable guest network – If visitors need Wi-Fi, disconnect it from the main network.
6. Deactivate UPnP and WPS – These functions can harbour security risks.

Firewall security

1. Check default rules – Block unwanted incoming traffic.
2. Minimise port forwarding – Only open necessary ports, e.g. for game servers or VPNs.
3. Activateintrusion detection/prevention – If your router supports this, it can recognise attacks.
4. Regular log analysis – Check the firewall logs for suspicious activities.

VLANs (virtual networks)

1. Logically separate devices – For example, separate smart home devices, guest Wi-Fi and your PCs into separate VLANs.
2. Set firewall rules for VLANs – Determine which VLANs are allowed to communicate with each other.
3. Secure management access – The router or switch should only be accessible from a secure VLAN.
4. Put IoT devices in their own VLAN – Smart lights & cameras are often insecure, so separate them!

Encryption and secure data transmission

The only secure communication is encrypted communication. Make sure that all data traffic is encrypted. Encryption also ensures that no third party can conceive a message and pretend to be the control centre. Only authenticated, known senders have access to the encrypted data traffic.

Practical measures for more security

• If possible, run cables inside the house and secure the ends with waterproof boxes
• Purchase an upgradeable (Zigbee) control centre, while the actual smart home devices are considered insecure. If the smart home devices are not patchable, the control centre offers protection as a flexible barrier.

• Less is more. Use a standard in the home, don’t rely on the cheapest manufacturers, but buy used (current) branded smart home devices with long-term support
• End-to-end encrypted connections (E2EE)
  • Apple HomeKit (via Secure Remote Access with iCloud)
  • Matter (uses AES-encrypted communication)
  • Signal-based controls (e.g. Zigbee with certificates)
• Encrypted communication in the network (TLS/SSL, AES, WPA2/WPA3)
  • Zigbee & Z-Wave → AES-128 encryption for data
  • WLAN devices → If they use TLS/HTTPS (e.g. Philips Hue Bridge)
  • MQTT with TLS → If configured correctly, MQTT is secure for IoT

Smart home devices are no different than computers, we need to take care of every computer as criminals target them for DDoS attacks.

Use of VPNs and secure remote access

If a data connection cannot be encrypted, then you need a VPN tunnel to encapsulate the connection. WireGuard and OpenVPN are the means of choice to reach your destination quickly and easily.