## 2 Background
### Smart Home Device  
While some authors directly define what is meant by a Smart Home (e.g., [13; 14]), we are more focused on the concept of a Smart Home (IoT) Device. Even if the term Smart Home Device is often used without a proper explanation (e.g., [15; 16; 17]), there is no single definition that one can refer to. Instead, the term has been defined in various ways with sometimes subtle but crucial differences. For example, [PERSON] et al. [18] define it as 'any single-purpose Internet-connected device intended for home use or a hub-like device that connects and controls multiple single-purpose devices' [PERSON] et al. [18]. This definition suggests that all devices must have some form of Internet connectivity in order to be considered smart; however, there also exist appliances that can operate when limited to the local network. In addition, ref. [16] shows that there are devices that, despite not having Internet, still show limited smart functionality. In [19], the author compares multiple definitions of Smart Home before presenting his own definition of a Smart Home Device as follows: 'A Smart Home Device is a thing, whose main functionality is extended with networking abilities to create a new one. The additional infrastructure for those devices, like a base or control station, also falls in Smart Home' [19]. This definition only requires 'networking abilities' [19], which also include the aforementioned devices that do not rely on an Internet connection. One aspect that both definitions agree on is that also additional devices like control stations, which may not have a perceptible impact on the home, should be considered as part of this environment. This is crucial as in practice the connectivity and smartness of a product may be shared between multiple appliances. (For instance, the Philips Hue Light Bulb can only be controlled with an appropriate bridge. Since 2019, there also exists a version that can be controlled via Bluetooth. In this paper, we consider the version without Bluetooth by default.) Overall, the latter definition offers a good starting point but also has some downsides that should be addressed in a custom definition. One thing that is not mentioned explicitly is that the things should be 'intended for home use' [PERSON] et al. [18] as the first definition points out. Just recently, the international standards community has decided in ISO/IEC 27403 [20] to call this _IoT-domotics_ and devote special attention as it requires 'user-friendly interface and usability' as well as being usable by the home users. Extending the general cybersecurity of IoT standard ISO/IEC 27400 [21], it recognises that '[i]n comparison with other IoT solutions, IoT-domotics have specific features and concerns. It is therefore essential to adapt the general IoT security and privacy principles to IoT-domotics and provide stakeholders with thorough and tailored guidelines in specific scenarios of IoT-domotics.' [20]. Finally, there exist applications that have not been possible with traditional devices at all, and therefore, there is no such thing that can be extended. For example, even if Amazon referred to Amazon Echo as a 'Smart speaker' ([[https://www.amazon.com/gp/product/B07](https://www.amazon.com/gp/product/B07) NFTVP7P]([https://www.amazon.com/gp/product/B07](https://www.amazon.com/gp/product/B07) NFTVP7P), accessed on 19 December 2024), it can also be seen as primarily being a voice assistant. Based on previously mentioned definitions, we identify our own definition of a Smart Home Device as follows:  
* A _Smart Home Device_ is a thing that is intended for home use whose functionality is only possible or whose main functionality is extended through means of networking capabilities including additional infrastructure contributing to this. * A _Smart Home_ is a system incorporating Smart Home Devices. Similar to Smart Home Devices, there also does not exist a single accepted definition for either the IoT or Cyber-Physical Systems (CPSs), and a distinction between the latter might often not even be clear.