𝘾𝙔𝘽𝙀𝙍 𝙏𝘼𝙇𝙆 ™ 😷 𝗛𝗮𝗰𝗸𝗶𝗻𝗴 𝗧𝗼𝗼𝗹𝘀 . 𝙇𝙚𝙖𝙠𝙨 & 𝙈𝙤𝙧𝙚

2022-05-19 19:56:07 To be continued باز کردن / نظر دهید

2022-05-19 19:55:33 All these nodes in this network create a consensus. They agree about what blocks are valid and which are not. Nodes in the network will reject blocks that are tampered with.
So, to successfully tamper with a blockchain

You will need to tamper with all blocks on the chain

Redo the proof-of-work for each block

Take control of greater than 50% of the peer-to-peer network.

After doing all these, your tampered block becomes accepted by everyone else. This is next to an impossible task. Hence, Blockchains are so secure. Next, in this beginner’s Blockchain development tutorial, we will learn how a Blockchain transaction works? باز کردن / نظر دهید

2022-05-19 19:55:05 باز کردن / نظر دهید

2022-05-19 19:55:02 Let’s see what happens when any user creates a new block. This new block is sent to all the users on the network. Each node needs to verify the block to make sure that it hasn’t been altered. After complete checking, each node adds this block to their blockchain. باز کردن / نظر دهید

2022-05-19 19:54:52 باز کردن / نظر دهید

2022-05-19 19:54:41 Distributed P2P Network

However, there is one more method which is used by blockchains to secure themselves, and that’s by being distributed. Instead of using a central entity to manage the chain, Blockchains use a distributed peer-peer network, and everyone is allowed to join. When someone enters this network, he will get the full copy of the blockchain. Each computer is called a node. باز کردن / نظر دهید

2022-05-19 19:54:37 This kind of mechanism makes it quite tough to tamper with the blocks, so even if you tamper with even a single block, you will need to recalculate the proof-of-work for all the following blocks. Thus, hashing and proof-of-work mechanisms make a blockchain secure. باز کردن / نظر دهید

2022-05-19 19:54:31 باز کردن / نظر دهید

2022-05-19 19:54:18 Proof of Work

Hashes are an excellent mechanism to prevent tempering, but computers these days are high-speed and can calculate hundreds of thousands of hashes per second. In a matter of a few minutes, an attacker can tamper with a block and then recalculate all the hashes of other blocks to make the blockchain valid again.

To avoid the issue, blockchains use the concept of Proof-of-Work. It is a mechanism that slows down the creation of the new blocks.

A proof-of-work is a computational problem that takes a certain to effort to solve. But the time required to verify the results of the computational problem is very less compared to the effort it takes to solve the computational problem itself.

In the case of Bitcoin, it takes almost 10 minutes to calculate the required proof-of-work to add a new block to the chain. Considering our example, if a hacker would to change data in Block 2, he would need to perform proof of work (which would take 10 minutes) and only then make changes in Block 3 and all the succeeding blocks. باز کردن / نظر دهید

2022-05-19 19:54:15 Therefore, changing a single block can quickly make all following blocks invalid. باز کردن / نظر دهید