The 2008 financial crisis exposed the world to the dark side of the Global Banking system. It introduced us to the whole new concept of Shadow Banking [Will write an article separately on this] and how it was significant enough to bring down the entire financial system. This made us ask the question: Is there an alternative to banks?
Bitcoin provides the most promising answer to this question, and provides the most usable and innovative alternate solution to the most important function of banks: Payments. Bitcoin is a cryptographic token that is used as a currency to enable users to make decentralized peer-to-peer payments on the Bitcoin blockchain at incredibly low transaction costs as compared to the existing payment system powered by banks.
What is blockchain?
At its most basic level, blockchain is literally just a chain of blocks, but not in the traditional sense of those words. When we say the words “block” and “chain” in this context, we are actually talking about digital information (the “block”) stored in a public database (the “chain”).
“Blocks” on the blockchain are made up of digital pieces of information. Specifically, they have three parts:
- Blocks store information about transactions like the date, time, and dollar amount of your most recent payment to the other party.
- Blocks store information about who is participating in the transaction. But this is recorded without any identifying information using a unique “digital signature,” sort of like a reddit username.
- Blocks store information that distinguishes them from other blocks. Much like you and I have names to distinguish us from one another, each block stores a unique code called a “hash” that allows us to tell it apart from every other block. Let’s say you made your splurge purchase on Amazon, but while it’s in transit, you decide you just can’t resist and need a second one. Even though the details of your new transaction would look nearly identical to your earlier purchase, we can still tell the blocks apart because of their unique codes.
A single block on the blockchain can actually store up to 2 MB of data. Depending on the size of the transactions, that means a single block can house a few thousand transactions under one roof.
How Blockchain Works
When a block stores new data it is added to the blockchain. Blockchain, as its name suggests, consists of multiple blocks strung together. In order for a block to be added to the blockchain, however, four things must happen:
- A transaction must occur. Let’s continue with the example of your impulsive Amazon purchase. After hastily clicking through multiple checkout prompt, you go against your better judgment and make a purchase.
- That transaction must be verified. After making that purchase, your transaction must be verified. With other public records of information, like the Securities Exchange Commission, Wikipedia, or your local library, there’s someone in charge of vetting new data entries. With blockchain, however, that job is left up to a network of computers. When you make your purchase from Amazon, that network of computers rushes to check that your transaction happened in the way you said it did. That is, they confirm the details of the purchase, including the transaction’s time, dollar amount, and participants.
- That transaction must be stored in a block. After your transaction has been verified as accurate, it gets the green light. The transaction’s dollar amount, your digital signature, and Amazon’s digital signature are all stored in a block. There, the transaction will likely join hundreds, or thousands, of others like it.
- That block must be given a hash. Not unlike an angel earning its wings, once all of a block’s transactions have been verified, it must be given a unique, identifying code called a hash. The block is also given the hash of the most recent block added to the blockchain. Once hashed, the block can be added to the blockchain.
When that new block is added to the blockchain, it becomes publicly available for anyone to view—even you. If you take a look at Bitcoin’s blockchain, you will see that you have access to transaction data, along with information about when (“Time”), where (“Height”), and by who (“Relayed By”) the block was added to the blockchain.
Is Blockchain Secure?
Blockchain technology accounts for the issues of security and trust in several ways. First, new blocks are always stored linearly and chronologically. That is, they are always added to the “end” of the blockchain. If you take a look at Bitcoin’s blockchain, you’ll see that each block has a position on the chain, called a “height.” As of Dec. 2019, the block’s height had topped 562,000.
After a block has been added to the end of the blockchain, it is very difficult to go back and alter the contents of the block. That’s because each block contains its own hash, along with the hash of the block before it. Hash codes are created by a math function that turns digital information into a string of numbers and letters. If that information is edited in any way, the hash code changes as well.
Here’s why that’s important to security. Let’s say a hacker attempts to edit your transaction from Amazon so that you actually have to pay for your purchase twice. As soon as they edit the dollar amount of your transaction, the block’s hash will change. The next block in the chain will still contain the old hash, and the hacker would need to update that block in order to cover their tracks. However, doing so would change that block’s hash. And the next, and so on.
In order to change a single block, then, a hacker would need to change every single block after it on the blockchain. Recalculating all those hashes would take an enormous and improbable amount of computing power. In other words, once a block is added to the blockchain it becomes very difficult to edit and impossible to delete.
To address the issue of trust, blockchain networks have implemented tests for computers that want to join and add blocks to the chain. The tests, called “consensus models,” require users to “prove” themselves before they can participate in a blockchain network. One of the most common examples employed by Bitcoin is called “proof of work.”
In the proof of work system, computers must “prove” that they have done “work” by solving a complex computational math problem. If a computer solves one of these problems, they become eligible to add a block to the blockchain. But the process of adding blocks to the blockchain, what the cryptocurrency world calls “mining,” is not easy [More on Bitcoin mining in the next articles]. In fact, the odds of solving one of these problems on the Bitcoin network were about one in 13 trillion in Dec. 2019. To solve complex math problems at those odds, computers must run programs that cost them significant amounts of power and energy and money.
Hence the Bitcoin Blockchain can verify the peer-to-peer transactions through a network of miners and is completely independent of banks. Also add to that incredibly low costs, as low as 0.5% of the transaction value. All these factors make blockchain one of the most promising technological invention of the century. Now that we have a fair idea of what a blockchain means, we will dive deep into Bitcoin & cryptocurrency. Please hang on till the next article post on Bitcoin and Bitcoin mining and what makes it a valuable asset for investment.