In the simplest terms, a blockchain is a chain of blocks containing information. First described in 1991, its intended use was to time stamp digital documents so that they could not be tampered with.
Each block in the chain contains some data, for example financial transactions, along with the hash of the block and the hash of the previous block, creating a secure chain. This cryptographic chaining means that if one block is tampered with, all following blocks will become invalid as the hash will no longer match, and similarly ensures the integrity of all previous blocks.
Blockchain was largely unused until 2008 when the technology was adapted to create bitcoin, enabling the direct transfer of assets between individuals. The use of a public blockchain to record the transactions removed the necessity for a mutually trusted third-party, meaning transactions could be carried out faster and cheaper.
How does it work?
The transactions recorded in the blockchain create a ledger, open and public to everyone. The ledger is distributed to everyone on the network, thus removing centralisation. Transactions are validated by special nodes on the network called miners, that discover new keys for each transaction, publish the key, and confirm the transaction to the rest of the network, ensuring the distributed ledger is synchronised amongst everyone on the network.
Security is enhanced by increasing the time it takes to generate new blocks, which is around 10 minutes for bitcoin, making the blockchain almost impossible to tamper with.
Uses of Blockchain Technology in Cybersecurity
Apart from the current and potential economic impacts of blockchain technology, there are many, varied proposed uses including notaries, health information, voting and personal data privacy.
For the cybersecurity industry, blockchain-based solutions for authentication and public key infrastructure can remove the need for Certificate Authorities, utilising the distributed consensus of trust properties of the blockchain and the open ledger system.
Blockchain technology can greatly increase the security of IoT devices addressing their inherent vulnerabilities. This can be done with the implementation of Smart Contracts, where IoT devices become nodes on the blockchain rendering the need for central control obsolete. The blockchain records tamper-resistant transactions between IoT devices, securing communication and preventing compromise of the network from threat actors.
Securing the Cyber World 