What is Blockchain?
“The blockchain is an incorruptible digital ledger of economic transactions that can be programmed to record not just financial transactions but virtually everything of value.”
Blockchain technology relies upon a shared record of transactions across a peer-to-peer network of computers. Every computer in the network has access to this shared record and uses special software to participate in the process. The computers on the network verify transactions in chunks of data called blocks. Once a computer verifies the transactions (typically by solving a complicated math problem), the network adds the block at the end of a chain of other blocks. These blocks stretch back all the way to the earliest transactions in the system in an unbroken chain.
Remember, it’s a long chain of blocks that is continuously growing and you can’t alter the chain going through some points in the past. If anyone tries to go to some point in the past and alter a block, then it will alter all the blocks since then. Since there are many peers of blockchain on a distributed system, we can see if any of the blocks have been altered. So, it will be very harder to alter or break any block in the past. That is why we say, a blockchain is immutable or unchangeable.
How Does The Blockchain work?
The very simple theme here is that it works as a system where records could be stored that could be verified by anyone and security is guaranteed. That’s why no one can alter the system by editing because everyone using the system would be watching. Blockchain stores information across the network of personal computers making them not just decentralized but distributed. This means no central authority owns the system, yet everyone can use it.
The people who run the system holds bundles of records submitted by others known as blocks in a chronological chain. The blockchain uses cryptography, which is a form of maths used in solving codes, to ensure that records can’t be altered by anyone. Digital coins like bitcoins, ethereum, steem etc use their own blockchain by tracking records of ownership over digital cash so only one person can be the owner at a time and a cash can’t be sent twice.
How blockchain technology keeps data secure?
Blockchain poises to make online transactions more secure while eliminating middlemen. Since blockchain is decentralized, no one entity or organization can control it. Whenever a new block is added to the chain, computers verify whether the previous transactions actually occurred. Because each block references the block before it, each transaction made down to the original block is confirmed. The blocks of those who attempt to cheat the system look different from other blocks. Since blockchain requires consensuses among all users, the cheater’s version of the blockchain will be disposed of.