# Embracing the Future Internet of Things +
## 6 Challenges and Open Issues
Considering the vertical elements in the bottom-up architecture, each level (i.e., devices, edge, cloud and applications) has its own security requirements. Each level is exposed to various types of security threats and possible attacks. Currently, there is a lack of and a certain need for a dynamic IoT security model for enabling mission-critical applications (e.g., autonomous vehicle control) and expected advancements in the IoT systems. Furthermore, for building trust and secure relationships between the IoT components, proper identification and authentication capabilities, and cooperation among these techniques in the IoT platform are currently missing. On the other hand, preserving privacy of data in IoT is an open challenge. The existing privacy protection policies for today's IoT include _encryption_, _anonymization_ and _obfuscation_ techniques, which are mainly for single services. However, new privacy preservation techniques in these interdependent services (e.g., searchable encryption, usage control, end-to-end encryption [39] with homomorphic encryption) by design principle for objects, devices, users, subsystems, and services are required. 3. _Critical real-time operation:_ The IoT of the future should be flexible and adaptable to sudden changes of the status and conditions of the infrastructures. This is due in order to have fast response to critical situations such as the increasing frequency of natural disasters due to the global climate change [40]. Infrastructureless alternatives for communication in networks [41] or easy-to-deploy infrastructures [42; 43] can help solve these problems. 4. _Trustworthiness evaluation_: A dual problem of the data access control is the control over data generation. Since the data is associated with real-world things reporting the status of them, only legit data sources should be allowed to report observations to a thing and, at the same time, the future IoT should be resistant to tampering attack. For that reason, it is a challenge to make a trustworthiness evaluation assessing which entity might be trusted and how trustful is the data generated [44]. 5. _Standardization_: Different layers of IoT have been studied within many standardization activities. However, there is little consensus regarding which layers and relevant techniques should be standardized and which layers should remain open to be designed. In addition, governments showed their interest in standardization and their involvement implies innovation restrictions due to ever stricter regulations. New requirements for IoT are defined by IoT organizations such as OpenFog, the Industry 4.0, Made-in-China 2025 [45], and the Industrial Internet Consortium. New activities are expected to come from ETSI, IEEE, IEC, ISO, FIWARE and oneM2M, to name a few. The advancements in standards should cover every ICT field such as connectivity (e.g., 5G and satellite connections), data format and models (e.g., semantic interoperability and data contextualization), sensing, actuations and security at all levels. A one-size-fit-all network management based on the same physical network infrastructure to exchange a variety of traffic and context is not efficient. Therefore, 3 GPP considers a more flexible network slicing technology that is one of the important features in 5G. Currently, the 3 GPP SA2 Working Group has defined the following three different categories of network slices based on the characteristics of service requirements: (1) extreme mobile broadband (xMBB), (2) ultra-reliable and low latency communications (uRLLC) or ultra-reliable MTC (machine-type communication), and (3) massive MTC (mMTC). First, high data rates and low latency are expected for the first type of services. Second, a critical level of latency and reliability are expected for the second types of services such as mission critical emergency response services. Third, machine-to-machine and device-to-device wireless communications are expected for the third types of service such as communications between lightweight IoT devices.