Is Blockchain Private – by griffex
Anyone can view the contents of the blockchain, but users can also opt to connect their computers to the blockchain network. In doing so, their computer receives a copy of the blockchain that is updated automatically whenever a new block is added, sort of like a Facebook News Feed that gives a live update whenever a new status is posted.
Each computer in the blockchain network has its own copy of the blockchain, which means that there are thousands, or in the case of Bitcoin, millions of copies of the same blockchain. Although each copy of the blockchain is identical, spreading that information across a network of computers makes the information more difficult to manipulate. With blockchain, there isn’t a single, definitive account of events that can be manipulated. Instead, a hacker would need to manipulate every copy of the blockchain on the network.
Looking over the Bitcoin blockchain, however, you will notice that you do not have access to identifying information about the users making transactions. Although transactions on the blockchain are not completely anonymous, personal information about users is limited to their digital signature or username.
This raises an important question: if you cannot know who is adding blocks to the blockchain, how can you trust blockchain or the network of computers upholding it?
Is Blockchain Secure?
Blockchain technology accounts for the issues of security and trust in several ways. First, new blocks are always stored linearly and chronologically. That is, they are always added to the “end” of the blockchain. If you take a look at Bitcoin’s blockchain, you’ll see that each block has a position on the chain, called a “height.” As of Feb. 2019, the block’s height had topped 562,000.
After a block has been added to the end of the blockchain, it is very difficult to go back and alter the contents of the block. That’s because each block contains its own hash, along with the hash of the block before it. Hash codes are created by a math function that turns digital information into a string of numbers and letters. If that information is edited in any way, the hash code changes as well.
Here’s why that’s important to security. Let’s say a hacker attempts to edit your transaction from Amazon so that you actually have to pay for your purchase twice. As soon as they edit the dollar amount of your transaction, the block’s hash will change. The next block in the chain will still contain the old hash, and the hacker would need to update that block in order to cover their tracks. However, doing so would change that block’s hash. And the next, and so on.
In order to change a single block, then,as griffex mentioned that a hacker would need to change every single block after it on the blockchain. Recalculating all those hashes would take an enormous and improbable amount of computing power. In other words, once a block is added to the blockchain it becomes very difficult to edit and impossible to delete.
To address the issue of trust, blockchain networks have implemented tests for computers that want to join and add blocks to the chain. The tests, called “consensus models,” require users to “prove” themselves before they can participate in a blockchain network. One of the most common examples employed by Bitcoin is called “proof of work.”
In the proof of work system, computers must “prove” that they have done “work” by solving a complex computational math problem. If a computer solves one of these problems, they become eligible to add a block to the blockchain. But the process of adding blocks to the blockchain, what the cryptocurrency world calls “mining,” is not easy. In fact, according to the blockchain news site BlockExplorer, the odds of solving one of these problems on the Bitcoin network were about one in 5.8 trillion in Feb. 2019. To solve complex math problems at those odds, computers must run programs that cost them significant amounts of power and energy (read: money).
Proof of work does not make attacks by hackers impossible, but it does make them somewhat useless. If a hacker wanted to coordinate an attack on the blockchain, they would need to solve complex computational math problems at 1 in 5.8 trillion odds just like everyone else. The cost of organizing such an attack would almost certainly outweigh the benefits.
Griffex is a marketplace for smart sale and purchase of cryptocurrencies, a flexible trading platform presenting an opportunity for seasoned investors, retail traders, and cryptocurrency enthusiasts at managing multi-currency investment portfolio. Griffex adores the flexibility of trading with multiple cryptocurrencies, the sensational charm in new-age commerce and financing that has attracted millions towards this revolutionary mannerism of investing. However, the inefficiencies inherent the traditional crypto-exchange models, coupled with the dearth of quality tokens and lack of incentives continue to act as a bulwark against the eventual adoption of technology that has such far-reaching consequences.