Blockchain Technology and Smart Homes
This section presents the structure on w'hich blockchain innovation is executed. It is progressive in nature and permits disseminated trust to guarantee security and protection. It makes the blockchain arrangement progressively suitable for use w ith the IoT in smart homes.
Security and Privacy Threats to Smart Homes
While smart homes possess great advantages, they are still defenseless against the possible dangers of vindictive digital assaults, because of the expanding assortment and sharing of the live data of property holders. Researchers predict that in 2020, malware, viruses, and web-based attacks will be driven into approximately a great many thousands . This could risk the security and protection of clients connected by means of smart home networks. The effort to achieve the security and protection of IoT-based smart homes has motivated IoT-based innovations from its early stages to the present development. When applied to smart homes, conventional security arrangements are considerably vulnerable to attack, because of the centralization of the system. This prompts the appropriate utilization of blockchain, w'hich is a disseminated, decentralized, open record. The three specific mainstays of blockchain are decentralization, transparency, and immutability, making it useful for guaranteeing security and protection to the proprietors of smart homes.
Blockchain as a Security Solution
Blockchain addresses each of the three CIA parameters: confidentiality, integrity, and availability. The widespread acknowledgment that blockchain innovation can protect transactions has opened new ways of implementing protection and security in the smart home. Blockchain has accomplished surprising execution for home access control and information sharing for smart home applications. The security issues of smart home are being resolved utilizing blockchain, specifically, because of the use of miners. The miner is responsible for keeping track of the heterogenous devices associated by means of the IoT. Additionally, blockchain encrypts the correspondence between different devices. The main levels of the structure are:
I. Smart Home
II. Cloud Storage
FIGURE 11.1 Overlay Architecture.
Smart Home Level: All the smart devices are introduced inside this level and are controlled through the excavator in a unified manner. At this level, the miner organizes overlay alongside service providers (SP), cloud storage, and clients’ devices (cell phones or PCs).
Cloud Storage: Distributed storage is utilized by the smart home devices to store and offer information.
Overlay: At this level, the hubs are isolated into groups, so as to diminish the delay in the system. A cluster head (CH) is chosen by every one of the clusters. The reason for CHs is to keep up an open BC, with two key records: requester key records and requestee key records. This overlay engineering is shown in Figure 11.1 . Further, the components of a smart home are shown in Figure 11.2, including:
i. Transactions: the communication occurring between network devices or overlay hubs.
ii. Local BC: monitors exchanges. It additionally keeps up an arrangement header which stores the clients’ strategy for approaching and active exchanges.
iii. Home miner: A smart home miner is a device that centrally processes incoming and outgoing transactions to and from the smart home.
iv. Local Storage: a reinforcement drive, to store information locally.
Cryptographic Aspects of Blockchain
In 2008, Satoshi Nakamoto  introduced the concept of blockchain. It is the underlying platform of cryptocurrencies (e.g. Bitcoin) that facilitates a P2P transaction system to eliminate third-party and double spent problem. It is not a centralized
FIGURE 11.2 Smart Home Based on Blockchain Architecture.
information hub. In blockchain, each portion of information is cryptographically associated with past portions, utilizing hashing characteristics, for instance, the secure hash algorithm (SHA-256). Such a portion of information is called a block, with associated properties such as block number, past blocks’ hash, timestamp (TS), exchange information, and nonce . Figure 11.3 portrays the blockchain plan, inside structure, and work process. The following steps describe the essential functionalities.
- 1. Every connected IoT device in a blockchain network is called a node. It stores all current transactions, which are in a waiting queue in a memory pool.
- 2. All the transactions are verified by a Merkle tree.
- 3. The validated and verified transactions are added to the block.
- 4. Miners change the nonce and timestamp to generate a hash of block.
- 5. The generated hash is compared by the system with the target.
FIGURE 11.3 Workflow of Blockchain.
- 6. If the hash value is found to be above the target value, then go to step 4.
- 7. If the hash value is less than the target value, then it is a successful case. It has successful verification of the PoW.