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How Can Blockchain Help Secure IoT Networks?

Internet of Things (IoT) is the collective name for smart devices connected to the Internet. These devices interact with other applications and each other, as well as with us. An example of this would be a smart refrigerator, which can detect when you’re running low on supplies and place an order online without any human input required. The only issue with these connected networks is the security risk. If a device, or the network it is on, is not suitably protected, it runs the risk of being targeted by hackers. The good news is blockchain technology could help secure IoT networks. Let us explain how…

What is Blockchain?

A blockchain is quite literally a chain of verified transaction blocks. The chain itself is chronologically arranged, with each block holding the data of a single transaction.

Every time a transaction happens, its details are added to the end of the chain, so the newest block is always last. Each block contains details of the transaction, the identity of any users that participated in that transaction, and the identification tags of the block. It also contains the ID of the block before it.

When users join a blockchain network, they can save a copy of the chain on their computer. When a new transaction occurs, their computer appends it to the end of the chain and saves the revised version.

Blockchain technology verifies this data across the network, which makes the information trustworthy.

What Makes Blockchain Secure?

No Single Database

The reason why a blockchain network is so secure is that records are not stored in a central location. Instead, there are copies of it on every user’s computer. In addition, each copy is verified against the rest of the network.


If there is a discrepancy in the records, the system is designed for a ‘consensus’, which means it will only accept the version that is saved on a majority of the computers.

This way, to manipulate the blockchain, a hacker would need to get access to multiple users and change at least 51% of the records in the network. This can be quite a daunting task, especially if there are millions of users.

Two Security Keys

To add to blockchain’s security, each user has a public and private key that they use to log data with. A hacker would need to obtain both in order to alter the information on a user’s computer, so if there were multiple users, each with their own copy, he would need security keys for each one of them.

Version Hash ID

Each block of the chain has two encrypted hash IDs, one of which is its own and the other is the hash of the block before it. When an already-verified block is edited, it gets a new hash, but the blocks after it don’t. This creates a discrepancy in the records and any such irregularity is quickly noticed.

So, to summarise:

By using blockchain technology, it is possible to maintain a record of all activity.

This record is:

  • Decentralised
  • Cannot be tampered with, once logged
  • Verified across the network
  • Scalable, reliable, and secure

How Does This Help Secure IoT Networks?

An IoT network is made up of multiple devices that are connected to the Internet, just like a blockchain network.

By using blockchain technology, all activity on IoT networks can be logged sequentially and securely. Any activity, once logged, cannot be edited, so if there are any changes, it is immediately apparent.

In addition, whilst it does not affect security, blockchain technology also makes the IoT network scalable. All the information is stored in individual devices, so, as a result, when the network grows, it does not need additional infrastructure to support it.