How Blockchain works ?

Blockchain technology has been gaining a lot of attention in recent years due to its potential to disrupt many industries. It has been hailed as a revolutionary technology that could transform the way we conduct business, govern societies, and interact with each other. But what exactly is blockchain technology and how does it work? In this blog post, we will take a deep dive into the world of blockchain and explore its underlying concepts and mechanics.

What is blockchain ?

At its core, blockchain technology is a decentralized digital ledger that is maintained by a network of users. The ledger records transactions in a secure, transparent, and tamper-proof manner. Each block in the chain contains a hash of the previous block, creating a continuous and unbroken chain of blocks. This unique feature makes the blockchain secure and immutable, ensuring that any changes made to the ledger can be detected and rejected by the network.

History of Blockchain Technology

Blockchain technology was first introduced in 2008 in a white paper by an anonymous person or group of people using the pseudonym “Satoshi Nakamoto.” The paper described a peer-to-peer electronic cash system that would allow secure, direct transactions without the need for intermediaries such as banks or financial institutions. This system, known as Bitcoin, was the first application of blockchain technology and remains one of its most popular and well-known use cases.

How Does Blockchain Technology Work?

At a high level, blockchain technology works by recording transactions in blocks and linking them together in a chain. Each block contains a list of transactions, a timestamp, and a unique code, known as a hash. The hash is generated using a cryptographic function, which creates a unique digital fingerprint for each block.

Once a block is added to the blockchain, it cannot be altered or deleted. This is because each block contains a reference to the previous block in the chain, creating an unbreakable chain of blocks. This is why blockchain technology is sometimes referred to as a “immutable ledger.”

To add a new block to the blockchain, a network of participants must reach a consensus on the validity of the transaction. This is done using a consensus mechanism, which is a set of rules and protocols that determine how transactions are validated and added to the blockchain.

What is Consensus and how many type of it exists ?

Consensus is a fundamental concept in blockchain technology that enables the network to agree on the state of the blockchain. In a decentralized system, there is no central authority that can make decisions on behalf of the network. Instead, all nodes on the network must work together to reach a consensus on the validity of transactions and the state of the blockchain.

There are several different consensus mechanisms used in blockchain technology.

Proof of Work (PoW)

Proof of Work is the most well-known and widely used consensus algorithm in blockchains. It was first introduced in the Bitcoin whitepaper and has since been used in many other blockchains, including Ethereum(now its working on PoS). In a PoW system, miners compete to solve complex mathematical problems, and the first miner to solve the problem is rewarded with cryptocurrency. This process is computationally intensive and requires a significant amount of energy, making it costly and inefficient.

Proof of Stake (PoS)

Proof of Stake is an alternative consensus algorithm that was introduced to address some of the inefficiencies of PoW. In a PoS system, validators stake their cryptocurrency to become validators and are chosen to validate blocks in proportion to the amount of cryptocurrency they have staked. This reduces the amount of energy required to validate blocks and makes the process more efficient. Additionally, PoS systems can offer greater security against certain types of attacks, such as 51% attacks.

Delegated Proof of Stake (DPoS)

Delegated Proof of Stake is a modification of PoS that allows token holders to vote for delegates who validate blocks on their behalf. This creates a more democratic decision-making process and allows token holders to have greater influence over the network. Additionally, DPoS can offer faster transaction times and greater scalability than other consensus algorithms.

Proof of Authority (PoA)

Proof of Authority is a consensus algorithm used in private and consortium blockchains. In a PoA system, validators are identified by a central authority rather than through a competition or staking mechanism. This allows for greater efficiency and scalability, as the system does not require the computational power or energy consumption of other consensus algorithms. However, this centralization also makes PoA less secure than other consensus algorithms.

Byzantine Fault Tolerance (BFT)

Byzantine Fault Tolerance is a consensus algorithm designed to address the issue of trust in distributed systems. In a BFT system, nodes on the network must reach agreement despite the possibility of malicious or faulty nodes. This is accomplished through a process of repeated rounds of voting until consensus is reached. BFT systems are highly secure and can handle a large number of transactions, making them suitable for use in enterprise applications.

Practical Byzantine Fault Tolerance (PBFT)

Practical Byzantine Fault Tolerance is a variant of the BFT consensus algorithm designed for use in permissioned blockchains. In a PBFT system, nodes must reach consensus despite the possibility of malicious or faulty nodes. This is accomplished through a process of repeated rounds of voting, where nodes exchange messages until consensus is reached. PBFT systems are highly secure and can handle a large number of transactions, making them suitable for use in enterprise applications.

Proof of Elapsed Time (PoET)

Proof of Elapsed Time is a consensus algorithm used in private blockchains. In a PoET system, nodes compete to become validators by performing a lottery based on the amount of time they wait. The first node to win the lottery becomes the validator and adds the next block to the blockchain. This process is energy-efficient and does not require the computational power of other consensus algorithms.