# Internet of Things and Blockchain Integration: Security, Privacy, Technical, and Design Challenges
## 4 RQ 3--BIoT Integration: Future Concerns and Trends
### Big Data  
The study of IoT real-time produced data is becoming increasingly popular. This sort of data is typically diverse and large in volume, yet it has large value for a business [11]. Analysis of IoT big data might uncover hidden useful and relevant information that may help users make better decisions. The business demands of BC financial services,  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt}} \hline \hline
**Challenge** & **Research Directions** \\ \hline \multirow{6}{*}{Big data [11; 25; 26; 70; 73]} & \(\bullet\) & Complex big data analytics methodologies on limited resources IoT devices are not directly possible \\  & \(\bullet\) & Providing authentication to the training datasets might be a huge difficulty \\  & \(\bullet\) & Promoting users to submit their data, using incentive mechanisms, in order to develop ML models \\ \hline \multirow{2}{*}{New business mode [76; 82; 96]} & \(\bullet\) & Trust issues among diverse users \\  & \(\bullet\) & Applications that minimize response time and maximize resource usage \\ \hline \multirow{2}{*}{AI [8; 26; 97; 98; 99]} & \(\bullet\) & Low-quality data can drastically damage the learning process \\  & \(\bullet\) & Access to the training dataset by hackers enables them to change attacks type \\ \hline \multirow{2}{*}{Quantum computing [77; 82]} & \(\bullet\) & Poses major security concerns for public-key cryptography-based BC systems \\  & \(\bullet\) & Quantum-resistant encryption development \\ \hline \multirow{3}{*}{Double-chained IoT [76]} & \(\bullet\) & Security methods developed lack a credit guarantee and data security \\  & \(\bullet\) & Data BC and transaction BC can be integrated into a double-chain mode \\  & \(\bullet\) & based on BC \\ \hline \multirow{2}{*}{Interoperability [8; 78]} & \(\bullet\) & Issues arise in data sharing: data exchange, data valuation, and data buildup \\  & \(\bullet\) & Multi-signature and BC shared ledger can be used to enhance interoperability \\ \hline \multirow{2}{*}{IoT, BC, and edge integration [12; 105; 142; 150]} & \(\bullet\) & Inclusion of edge computing or SDN to enhance the security and privacy \\  & \(\bullet\) & Edge and fog also have their own concerns that should be considered \\ \hline \hline \end{tabular}
\end{table}
Table 13: Summary of future challenges and directions.  
for example, are significant, necessitating the addition of big data and related analytic capabilities to the ledger offered by the whole BC [117]. A group of more than 40 Japanese banks has inked a contract with Ripple to simplify the movement of payments between bank accounts and undertake real-time and low-cost transactions [70; 145]. Another example was recently released by the Indian government by setting up a gene database system based on block linkages for 50 million people [70].  
Despite these efforts, bringing traditional big data analysis to the IoT is a big challenge due to the following concerns [26; 68; 73]: (1) resources and computational capabilities are limited for IoT devices, which makes it impossible to use complex big data analytics methodologies on IoT devices directly. A potential alternative is to upload the data to clouds for processing and big data analysis, although this might result in significant latency and privacy problems; (2) the digital signature of a public/private key guarantees privacy in the BIoT. However, anonymous data may make decrypting and executing big data analysis a challenge and a time-consuming operation that leads to ineffective data analytics.