website solutions

Blockchain in Internet of Things: Challenges and Solutions

Last Updated: November 17, 2021By Tags: , ,

IoT (Internet of Things) is experiencing exponential growth, and this growth is going to increase in recent years. This growth causes many security and privacy vulnerabilities. Traditional security and privacy solutions are not capable of handling IoT devices.

The blockchain that underpins the cryptocurrency has made it possible by using the peer-to-peer model and decentralized approach. However, the blockchain approach is very computationally hefty and expensive that involves a high bandwidth bottleneck and delays that are completely not suitable for IoT devices. You can communicate with it professional services companies and get IoT solutions

How blockchain provides security using private authentication?

This paper shows how you can use blockchain technology to make IoT devices more secure. Computers are hard to use on the internet. But the security of IoT (Internet of Things) devices is good. Blockchain technology makes it hard for people on the internet to access things that happen on their devices. This paper uses different types of blockchain models for distributed trust methods to ensure the decentralization topology.

The purpose of this architecture is to build smart homes. To do this, we will use cheap sensors and IoT (Internet of Things) to make homes smart.

There are many solutions, but this one created latency, delays, overheads or even compromised somebody’s privacy.

How does blockchain work?

The answer to the problem lies in the technology that boosts cryptocurrency that is Bitcoin. Bitcoin uses the same networking peer to peer model that has been used by Bit Torrent for many years. Here we use a public key for the user identity to provide privacy.

If the miner is able to solve the cryptic puzzle, it will become a new block in the blockchain. In this case, multiple miners can perform the same transactions at a time, but this facility comes with a cost that multiple miners have to use their resources on the same transaction that, in the end, turn into a delay.

Use of Blockchain for addressing the IoT security issue:

  1. Decentralization/ Distribution: By using this approach, we eliminate most of the flows in the centralized approach like many to one traffic flow. This process increases the scalability, and the reliability of the network decreases the delay and possibly overcomes the failure rate.
  2. Secrecy: In most cases, the IoT (Internet of Things) devices come with the security of privacy and the feature to keep the identity private.
  3. Security: IoT is a heterogeneous environment where security is very important. Here blockchain secures the devices from untrusted parties.

Challenges for the adaptation of Blockchain for IoT devices:

  1. As we know that IoT devices are resource restrictive, but blockchain devices are very expensive and task intensive.
  2. Expansion in IoT devices is a common thing from hundreds to millions of devices in a few years, but in blockchain, the node devices increase very poorly.

Our main focus in this paper is to deliver the blockchain-based IoT security mechanism that delivers lightweight distributed security and privacy for IoT.

Blockchain-based IoT architecture for smart homes:-

Let’s take an example for a better understanding of the architecture. Alice has equipped the home with smart devices like door locks, smart cameras, smart temperature, IP cameras, and many other sensors. There are three major things that a smart home needs that are IoT devices, local blockchain, and local storage space.


Overlay Network

This network is the same as a peer network in the blockchain. To decrease the overhead, the nodes in the cluster and the node is selected as a cluster head (CH). The working of cluster head has some major functionalities is given below:-

  1. Requester’s private key: All the list of the private keys is controlled by the CH because the PK can access the data in smart homes.
  2. Forward list: There are many cluster heads in the network. It’s the CH job to send the transaction list to all the other CHs in the network.

Cloud Storage

Sometimes, it happens that some smart home IoT devices like to store data online. The possibility is that it stores the data in cloud storage provided by Google, Microsoft, or some other private company.  By this method, only one with the key will be able to open the block.


The devices can store the data in local storage, cloud storage, or shared storage. As you can see in the above figure, let us assume that Alice has opened an account in the cloud storage and allowed her IoT devices to store the data in the cloud. When an IoT (Internet of Things) device needs to store the data in cloud storage, it sends the data to the miner. Then the miner checks that is the IoT device stores the data or not. Then after getting permission, the miner extracts the previous hash and block number, then the miner creates a random ID and sends this ID to the storage device.


The service provider can access data whenever it wants. To obtain this kind of functionality, the service provider makes and assigns a transaction. The service provider and the home miner signed the transaction and sent it to the head of the cluster known as CH. The CH sends the output as yes in the form of 1 and no in the form of 0. In smart homes, it happens much time when the homeowner or CH needs the entire record. This causes a great overhead on the network.

  1. When the user in the smart home wants to access the data, the miner in the home just sends the assigned number of blocks and the hash value of the storage data.
  2. In the case, the above possibility fails, then the miner tries to send the minimum important data that fulfill the smart home user needs for the time’s sake.


Many times, it happens that the smart homeowner wants to check or monitor the real-time data of the sensors like the user wants to check the temperature of the geyser or check the real-time feed of his/her home.

Decentralized Faith (Trust)

Here, we have discussed that the most important thing about the distributed and the decentralized thing is to generate trust among the whole network. It is difficult to describe the faith among different networks and the entities in the network. So, we have made a table for distributed faith.

Overhead Assessment

The estimation of the extra work done by the miner for the mining process in the above-described architecture has been described by the table given below:-

  1. The number of clusters is donated with N
  2. Block Size is donated with BS
  3. Trust Level is donated with TL
  4. Transfer from source to storage is donated with T
  5. Blocks in BlockChain is donated with B


Like always, security is always a great concern in the networking world, especially with IoT devices because of their lightweight nature. In this paper, we have provided the basic work and security for the IoT devices using the miner of blockchain for smart homes.

The question is still there how to reduce the DoS attacks, and 51% of attacks are on establishing decentralized trust. In this paper, we have shown that how lightweight devices are. That cannot provide security to themselves can get benefit from the technology of blockchain for security and privacy.