What is Blockchain?
A blockchain consists of a secure chain of transaction-recording blocks. Each block has a unique identifier (called a hash code) that ties it to the blocks that came before and after, making a single block difficult to alter without changing the entire chain. Computers connected to the blockchain network are called nodes and store data each time the blockchain is updated. In order to alter any part of the blockchain, a majority of nodes must agree.
The Power of Decentralization
The advantage of blockchain for cybersecurity lies in decentralization. This means that the IoT network isn’t controlled by a single central authority. Each node on the blockchain operates on its own and holds the same data copies as each other node. This way, if a hacker shuts down a single node, or even several nodes, the network can still operate. Likewise, if a hacker alters or attacks a single node, the other nodes on the network still hold the correct uninfected data and can override the attack.
Securing the IoT Network with Blockchain
There are many ways blockchain can be leveraged to secure the IoT network:
A centralized point of data storage gives hackers a single entry to exploit sensitive data. Decentralized data stored within the blockchain network denies hackers a single point of entry. If a hacker does access a node, the data cannot be destroyed or altered because the larger network of nodes will verify what the data should be and deny the change.
With a central authority governing cybersecurity, hackers can shutdown or infect the authority to dampen security protections. However, on the blockchain, nodes can identify and lockdown nodes behaving strangely, saving the network from a potential security breach.
Disrupting Denial of Service (DoS) Attacks
One method hackers use to initiate DoS attacks is to infiltrate a centralized Domain Name System (DNS). By accessing the IP address of a website, hackers can shut down the site or redirect traffic. Blockchain decentralizes the DNS, denying hackers a single exploitable access point. Any change to the IP address will be denied by other nodes that hold the correct data.
Protecting Data Transmission
Data is vulnerable while in transit, which hackers exploit to alter or delete data. Since blockchain tracks every transaction, altered or deleted data is identifiable by invalid hash codes. The correct version of the data can be restored by other nodes on the network that hold the record before the data was altered.
Verifying Software Downloads
Traditionally, software downloads are verified through known identification codes. However, a code from a verified source can still be infected with malware. Blockchain takes verification a step further by tracking all transactions. If a potential download has been tampered with, it can be identified by its altered hash code.