In many ways, blockchain technology addresses the issues of protection and trust. Lets discuss Is Blockchain Secure or not? First and foremost, new blocks are often stored in a sequential and chronological order. That is, they are often added to the blockchain’s “top.” When you look at the blockchain of Bitcoin, you’ll notice that each block has a location on the chain called a “height.” The block’s height had reached 656,197 blocks as of November 2020.
It is extremely difficult to go back and change the contents of a block. After it has been added to the end of the blockchain unless the majority agrees. That’s because each block has its own hash. As well as the hash of the block before it and the time stamp listed earlier. A math function converts digital data into a string of numbers and letters, resulting in hash codes. The hash code changes if the information is changed in some way.
Here’s why that matters in terms of protection that weather Is Blockchain Secure or not. Let’s say a hacker tries to change the blockchain in order to steal Bitcoin from the rest of the world. If they changed their single copy, it would no longer match the copy of anyone else. When anyone else compares their versions, they’ll notice that this one stands out. And the hacker’s version of the chain will be dismissed as illegitimate.
How to Succeed?
To succeed in such a hack, the hacker will have to manipulate. Change 51 percent of the blockchain copies at the same time. Ensuring that their new copy becomes the majority copy and therefore the agreed-upon chain. An attack like this would cost a lot of money and energy. Because they’d have to redo all of the blocks because the timestamps and hash codes would be different now.
The cost of pulling off such a feat will almost certainly be insurmountable. Given the scale of Bitcoin’s network and how quickly it is increasing. This would not only be prohibitively costly, but it would also be futile. Such actions would not go unnoticed by network members, who would note such significant changes to the blockchain. Members of the network will then fork off to a new, unaffected version of the chain.
This would cause the value of the attacked version of Bitcoin to plunge. Rendering the attack futile since the bad actor would be in possession of a worthless asset. If a malicious guy attacked Bitcoin’s latest fork, the same thing will happen. It’s designed this way so that participating in the network is much more financially rewarding than targeting it.
A blockchain is a collection of blocks that store data in hash functions with timestamps. Ensuring that the information cannot be altered or tampered with. Data manipulation is highly impractical since data cannot be overwritten, protecting data and removing centralised points that cybercriminals often target.