Why using 433 MHz in smart locks is not a good idea

In the world of electronic locks and connected access systems, technology is advancing at a great speed. Every year, new options emerge that promise simpler installations, greater range or lower cost. However, when it comes to physical security and cybersecurity, not everything that seems convenient or affordable is necessarily reliable.

One of the most common debates in this field centres on the use of the 433 MHz frequency, which some manufacturers promote as a “long-range” alternative technology to well-established protocols such as Bluetooth Low Energy (BLE).
But what exactly is this frequency, and why can it pose a risk in smart locks? Let's take a closer look.

What is the 433 MHz frequency and why do some locks use it

433 MHz is an open radio frequency used by countless everyday devices: garage door remote controls, weather stations, motion sensors and more.

Its main advantage is allowing wireless signals to be transmitted over long distances with low power consumption, without the need for licences or complex configurations.

As a result, some electronic lock manufacturers have adopted this technology, claiming it reduces costs and simplifies installation by requiring fewer gateways to communicate with devices.

However, although it may seem like a technical advantage, it poses a significant risk for security systems, as this frequency was not designed to protect sensitive information or resist tampering or theft.

433 MHz: a frequency that puts security at risk

At first glance, 433 MHz solutions may seem appealing. They have:

• Greater coverage with less infrastructure.

• Cheaper installation.

• Modules that are easy to implement.

However such advantages can quickly become problematic when critical factors such as interference, privacy and resistance to attack come into play.

433 MHz is an open, shared frequency used by everything from garage door remote controls to weather stations and home sensors. This leads to signal collisions, instability and temporary outages, as well as being prone to attacks using readily available equipment.

Common vulnerabilities in 433 MHz systems

The main problems with this technology are not just frequency saturation, but also how easy and inexpensive it is to exploit.

With low-cost tools such as SDRs (Software Defined Radios), an attacker can:

• Intercept and copy signals (replay attacks).

• Block communication through deliberate interference (jamming).

• Capture encrypted data packets and analyse them with ease.

Although some implementations use AES-128 encryption, this does not guarantee real protection. It secures the message content, but it does not prevent attacks on signal availability or manipulation. And when encryption keys are fixed or poorly managed, the security level drops drastically.

In short, 433 MHz is an outdated and risky technology for a connected smart lock.

BLE: the leading security standard for smart locks

Compared to the limitations of 433 MHz, Bluetooth Low Energy (BLE) offers a modern, secure and extensively audited architecture. It is the foundation of the most advanced solutions on the market and the standard trusted by major manufacturers.

Here are some of its key advantages:

• Robust encryption and secure authentication. BLE incorporates AES-128 encryption, session control and secure pairing protocols, such as LE Secure Connections.

• Greater resistance to interference. Uses frequency hopping, constantly changing channels to avoid signal collisions.

• Continuously evolving ecosystem. BLE is a living standard, with regular updates, patches and support from the tech community.

• IoT compatibility. BLE is the foundation of platforms such as Matter; the standard backed by Apple, Google and Amazon for the secure configuration of smart devices.

No technology is perfect, but BLE has proven to be the most mature, reliable and scalable option so far for electronic access systems.

Practical comparison: 433 MHz vs BLE

Omnitec's approach: security without shortcuts

The conclusion is clear: greater range does not mean greater security. At Omnitec Systems, we offer electronic hotel locks designed with security in mind - not commercial convenience. That's why all our BLE solutions include advanced encryption, secure authentication and safe remote management via gateways.

Models such as the OS SLIM and EVO range demonstrate that a connected lock can offer both extended range and genuine security.

If the global IoT standard relies on BLE, there is simply no reason to choose vulnerable frequencies like 433 MHz. BLE does require more advanced infrastructure, that's true, but it provides the peace of mind and robustness that an online lock needs. At Omnitec, our position is clear: security is non-negotiable.

So are you ready to take the plunge towards a secure, connected solution? Find out about Omnitec Systems' security solutions. We'll help you find the perfect balance between technology, control and protection.