So What is Blockchain?
- David White
The latest buzzwords in technology for sure, but if you think that Blockchain is something that your technicians use when changing engines, you better read on…
Fundamentally, a blockchain is effectively just a database that stores information. However, blockchain has the ability to store information with unique attributes. Blockchain technology offers the following features.
Decentralisation. No single party has control over what goes into the blockchain. Arguably the most important feature of blockchain is this decentralisation. Copies of blockchain ledger are stored and updated on computers all over the world. This means that no central authority can make decisions.
Consensus. Because so many different parties store the exact same copies of the blockchain ledger, the majority has to agree on what is being added to the blockchain.
‘Add Only’, meaning that existing information can not be edited and changed. Only new information can be added. And new information can not conflict with what has already been added.
A relatively easy way to explain how a blockchain works in practice is to look at the most well-known applications of blockchain, a Bitcoin transaction. However remember that Bitcoin is to blockchain what e-mail is to the Internet, an application based on infrastructure.
So if I want to send 1 Bitcoin to you, everyone on the Bitcoin ledger can see that I have 1 Bitcoin and you have none. I can send you 1 Bitcoin and the network will see this and update every ledger. But in theory, I could change my copy of the ledger to show that I have 2 Bitcoins. But with blockchain technology, this is impossible. Why?
The information stored on a blockchain is stored in groups, called blocks. Each block is time stamped and linked to the previous block, creating a linear chain of blocks, hence blockchain.
Each of the above block contains 3 types of information.
- Transactions data
- The block’s hash
- The previous block’s hash
The hash is effectively the block’s fingerprint – a unique string of numbers that identifies each block. These numbers are automatically calculated based on the information stored within the block. If the block’s stored information is changed then by default you then change the hash of the block and thus its identity.
The hash of the previous block sits in each block, which is what creates the chain of blocks. This is what makes cryptocurrency so secure.
Each block contains the 3 elements listed above, but see below what happens when the information is tampered with in block 2
Block 3 contains the hash of block 2 but when block 2 is changed, so does its hash meaning that everything in block 3 and beyond becomes invalid, breaking the chain.
It would then be essential to recalculate the hashes of every block that has changed. But that is just the start. The Bitcoin network makes it intentionally difficult to find these hashes. On average, and in the most simplistic of terms the hash for a block is found every 10 minutes by computers constantly guessing random numbers and seeing if they fit. This process is known as proof of work and is carried out by powerful computers. This is ‘Bitcoin mining’.
So for every block manipulated 10 minutes of intense computing work to mine each block would be required. And that's just the local copy!
As the Bitcoin ledger exists over tens of thousands of computers globally it would be required to access over 50% of the world's computers. Insanely expensive and virtually impossible. Hence the reason blockchain technology is considered to be so secure.
Applications of Blockchain
Whilst in its infancy many experts consider that blockchain technology will radically change many industry sectors. Banking is the most obvious, negating the requirement for middlemen such as banks. Think also of voting rights, supply chain systems where access to the current status and stock levels in immediate and indisputable.
For the car dealer, there are multiple potential applications of blockchain. Accepting cryptocurrency as a means of payment for vehicle deposits, monthly payments, and the outright purchase is one. But also think of the benefits of the life history and specifications of vehicles stored on the blockchain. That 60-year-old Jaguar E-Type with a full-service history, repair records, parts, and maintenance stored forever digitally.