Blockchain Basics

4 min readOct 24, 2020


Kishanthan Moorthy, Developer @iLabs

Blockchain, this word we continuously think of when we talk about how technology has changed. this is the better way to transforming the use-cases for various areas. blockchain is undoubtedly a notable revolution in systems of record. it described as ‘magic boxes’ due to the numerous high-level use cases promised by block-chain.

What is that

The basic level of block-chain technology composed of cryptographic algorithms. the first blockchain technology was introduced by Satoshi Nakamoto from his conference papers. this was helpful for maintaining traditional databases to become a trusted record by using cryptography algorithms. digital decentralized technology that is maintaining the transactions which happen over a peer-to-peer network.

Kishanthan Moorthy, Developer @iLabs


The main goal of the blockchain is to create decentralized, distributed records. that means to maintain a history of transactions or updated states. this will be an output of the records. A famous example for the blockchain is bitcoin here blockchain used to maintain history transaction records.

every transaction recorded into the blocks. for the block creation, they are using cryptographic algorithms. so it is restricting some functionalities for the security advantages so it becomes secure and reduces vulnerability for the hacking. so money and records won’t be lost or stolen.

most of the time Hash function and public-key cryptography used as cryptography algorithms. These things help to create security ecosystems.

Hash Function

A hash function is a mathematical function. it will produce output in a fixed range of numbers. The 256-bit hash function most of the time for used blockchain process but 128,512 hash functions also there. hash functions have some different advantages

output is totally different from input things so we can’t see similarities, this output looks like a large number and the most important point is this is a oneway process we cannot get back from this process.

hash function consuming input as the content of the blocks that mean transactions. this hash value act as the identity of each block. for the hash value creation they are using the Markle tree process for generating hash value.

every block is connected by using a hash value that looks like a linked-list data structure. so every block has a reference for the next block hash value. if anyone tries to change inside of the record or transactions that hash value also changed so that connectivity will break so we can easily identify the corrupted block. other think that hacker need to change every blocks hash value that is a very powerful process and it’s consuming more time

publicKey Cryptography

First, we have to see the use-cases we can encrypt a message that only can recipient can read it, provide a digital signature for a given message at the same time verify the facility to identify modified or transit. This cryptography function has two types of key values first one public key and the second one private key

public key is unique for every participant it acts as an identity for find a receiver so this key can be known by other participants. but private key not like that this is secure and private for everyone this key is invisible for other participants.

Okey how these two are working… there are two participants are there A and B. so A try to send a message to B. and this message only read by B. so A knows B’s public key so A use that public key to encrypt that message and sent it to B. so B has their own private key so by using that decrypt that message. without B’s private key can’t decrypt the message.

for this sector, if a participant fails to secure the private-key it will create a big vulnerability for Hacking. and another biggest problem is we all are heard about Quantum computers. it can easily break the public-key and their key combination so traditional blockchain no longer works. but this thread can be fixed with the upgrade.

Originally published at on October 24, 2020.




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