How Does a Block of Data on a Blockchain Get Locked?

Although blockchain technology for some is known exclusively because of its relationship with cryptocurrencies, such as Ether or Bitcoin, it is no more than an electronic row of tied and proven records.

Some of the merits of this digital “ledger” are that it is tamper-evident and can be instantly updated online. These features make the technology ideal for data verification, data access, and identity safeness, which act as blockchain’s most typical use cases.

Because blockchain is a distributed ledger, it allows many specific security measures against “locking” data blocks so integrity and immutability are maintained. This capability is often used by any blockchain development agency to reinforce security protocols for their clients.

But how does a block of data on a blockchain get locked? And what does it mean to actually lock data on the blockchain?

What Is a Block in Blockchain?

A block is literally a digital container that carries a certain portion of data. Each block has several obligatory parts that make it work as it works within the chain.

First, it’s the block header, which encloses the time the block was formed and a hash (special code) that unites it with the previous block.

As a result of the gradual addition of each block to the next, a chain is formed in which when one block changes, all the others change as well.

Inside the block, you’ll find the transaction data, which could be records of transfers, exchanges, or other actions registered within the network.

How Data Is Added to a Block

Have you ever wondered how each additional block added to the blockchain strengthens the integrity of the entire chain? Indeed, In fact, if you look into it, there is no secret at all.

Once data is thrown into a blockchain, it goes through a few steps. They are always the same. First, computers on the network, known as nodes, compile and verify transactions.

After that, miners or validators double-check each transaction to prevent any errors or fraud, for example double-spending, and confirm it follows the blockchain directions.

When the operations are verified, they’re positioned in a pattern/frame called a Merkle tree. This structure combines pairs of transaction summaries into a single, main summary, called the “root” hash.

The Merkle tree is responsible for keeping everything organized, and it makes it easy for all transactions in the block to be verified without using up too much space. After these steps, the data is ready for sealing it into the blockchain.

Hashing: The Digital Lock

Hashing is a way of converting data into a unique, fixed-length hash using a secure algorithm SHA-256. This hash functions as a digital fingermark for the data, and even a subtle change in the records would create a totally different hash.

For example, SHA-256 takes the input data and creates a 256-bit hash, which makes each block’s hash individual.

This unique hash “seals” the block, keeping the data safe. Since any change in the data would lead to a renewed hash, it’s easy to tell if anyone tries to modify a block.

Proof of Work (PoW) or Proof of Stake (PoS): The Consensus Mechanism

Consensus mechanisms are ways for nodes in a network to agree on what’s true or correct. Picture a group of friends who need to decide whether to visit a party or skip it.

They might all vote, or one friend might make the choice taking into account everyone’s input, or maybe they rotate turns. These are all different ways to come to a decision as a group.

The same applies to the blockchain. However, different consensus mechanisms follow different paths:

Proof of Work (PoW): Secure But Energy-Consuming

In Proof of Work, participants race to solve entangled math puzzles using their computers. The first one to cope with them gets to adjoin a new block and score some remuneration.

PoW is extremely resource-draining, as it demands much energy to run. Still, it guards the network against someone with sabotage intentions.

To change a block, a hacker would have to do over all the work for it and the ones after, which makes messing with the data not worth the trouble.

Proof of Stake (PoS): Resource-Sensible But Risky

Proof of Stake, in turn, takes a different direction. Per this mechanism, validators are assigned to generate new blocks based on the quantity of assets they possess and are willing to “venture” as deposit.

The more coins a validator wields and bets, the higher the likelihood they will be appointed to prove the legality of the succeeding unit.

This method is much more sensible and rational than PoW, becuase it doesn’t depend on heavy computational contributions.

PoS also protects the ledger by obliging validators to risk their own assets, creating therefore a convincing incentive to follow the decentralized principles and act honestly.

In conjunction with smart contracts, PoS can facilitate automated transactions that claim little supervision from the human side.

Linking Blocks Together with Hash Pointers

Blockchain’s security comes from linking blocks together with hash pointers, which connect each block to the unique hash of the foregoing one, creating a healthy, immutable chain.

Immutability means that if someone attempts to change the data in a block, the hash will be touched too, which altogether breaks the link to the next block and shows that tampering has been made.

This linked chain of hashes forms a ground for security in a blockchain because it constructs an unbreakable sequence that shuts each block in place, making any alteration of data extremely complicated.

Digital Signatures and Security

Digital signatures confirm that transactions are genuine and approved. Any member of a blockchain owns two keys: a private key that they use to sign transactions and a public one that other people could use to prove that a transaction actually was authentic.

Put simply, only the person with the private key can start a transaction, and the digital signature proves it’s real.

By using digital signatures, blockchain keeps data protected and confirms the identities of everyone involved, adding a firm shield of security and trust to each action made.