IoT 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 prefessional 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 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. But there are some problems with having so many devices interconnected. Devices that share information with each other can be hacked, and people can find out private things about you which they should not know (like your location or what you like).
On the one hand, the IoT devices collected data can be used for personalized services. On the other hand, it can be used to track somebody’s behavior. Some people are worried about security and privacy. 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 a public key for the user identity to provide privacy. The whole blockchain consists of blocks linking together as a ledger/ register to be called a blockchain.
The blockchain consists of miners, and in peer to peer, any node connected in the network could be a miner, and the miner will solve the puzzle of cryptography that will be very computation and resource-intensive, which is called Proof of Work. If the miner is able to solve the cryptic puzzle, it will become a new block in the blockchain. Whenever someone wants to do the transactions, the news of the transaction will be broadcast to the whole network. When the transaction is received by the miners, they validate the transactions by verifying the digital signatures which are in the transaction. 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:
- 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.
- Secrecy: In most cases, the IoT devices come with the security of privacy and the feature to keep the identity private.
- 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:
- As we know that IoT devices are resource restrictive, but blockchain devices are very expensive and task intensive.
- IoT devices are known for their negligible latency, but on the other hand, the miner’s mining tasks are time-consuming.
- 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.
This network is the same as a peer network in the blockchain. Each node Tor browser is used for blockchain purposes and generates privacy in the IP layer. 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:-
- 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.
- 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.
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. The user data will be stored in the cloud with the identical block number that is assigned to it in the blockchain. For the user to authenticate the data, the block number and the hash table will be used for this purpose. When the data is successfully stored in the cloud, we use the Diffie-Hellman security algorithm to encrypt the block number. 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 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. To save the network from then overhead, we define some different policies to tackle this problem is given below:-
- 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.
- 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. In the picture below, we have shown how the transaction will be done from the device to the machine to the miner to network to the user.
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.
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 that cannot provide security to themselves. Can get benefit from the technology of blockchain for security and privacy.