I found one of the comments in this paper very insightful: AI is an automation tool for decision making and it can optimize the way we store data as well as decide on which data we want to store. This characteristic of AI can benefit IoT in controlling facilities in a system. The data that is produced by IoT needs a large and secure medium for storage. This is where blockchain comes in.
Recently I read an article on risks of applying blockchain in IoT (I linked it down below). I extracted and summarized some of the most interesting and important aspects of this source.
Challenges and risks of using blockchain in IoT:
Blockchain makes use of decentralized networks in its operation. However, as the size of the ledger increases, the network might become centralized instead. A record management system is required to keep the centralized network in check.
- Processing power and time
An IoT system consists of many devices with different levels of processing power. Not all devices can run the same encryption algorithms. In addition, some parts of the IoT system might experience lag.
Due to the decentralized network in blockchain, the ledger record should be stored on the nodes. The amount of storage needed increases over time, and might even surpass the capabilities of the facilities in an IoT system.
As blockchain is a novel technology in this era, human resources with strong technical background and skills are still scarce. To overcome this issue, many organizations and enterprises should hire specialized vendors to set up blockchain solutions. However, it is often hard to find vendors with high credibility.
Despite blockchain’s high security, it is still prone to malicious activity from other parties. This can happen especially on a public blockchain, where many users have a private key to “sign” on transactions as most systems lack multi-factor authentication. In addition, losing the account’s private key means losing the account’s data as well.
- Legal issues
The laws governing blockchain and its usage differ among countries. Many businesses prefer to avoid blockchain altogether due to the risks of legal issues.
All in all, there are many elements to consider when applying blockchain in IoT, and I think that among the four convergence cases you give (AIoT, IoT Blockchain, Blockchain AI, and AIoT Blockchain), IoT Blockchain and AIoT are much more studied, yet there are still many unknowns ahead even for these convergence cases.