ENTIRE QUESTION
(1) Write the definition of blockchain. And how our data on the Blockchain is protected from hackers. ? And write details about Data, Hash and Previous Hash tag and explain via screenshot.
Nowadays it is very common to hear the term blockchain, especially if we talk about cryptocurrencies. This term originates in 1991 with Stuart Haber and W. Scott Stornetta who presented a work with this technology, however, it became known in 2008 when the Bitcoin technical document was presented to later create this cryptocurrency. At present this technology is not only used in the matter of cryptocurrencies, but it is also used in the registration of documents, properties, patents and smart contracts.
The word Blockchain is a word composed of two others that are: Block, which when translated means that it is a square or rectangular object that is made up of particles, and the word Chain, which when translated means that it is a chain, that is, an object with which you can link different objects to keep them together. With these concepts we can say that Blockchain is a chain of interlocking or interconnected blocks that are made up of particles.
By relating the previous concept to the topic of cryptocurrencies, we can say that Blockchain is a chain of blocks that stores specific information. We can also see it as the public ledger in which all transactions are supported. The blockchain network works as the safest ledger that exists, which cannot be modified or altered by anyone. All stored data cannot be deleted. This network also functions as a folder of records and works in a decentralized way, that is, without the intervention of government entities or conventional banks.
Within the blockchain, each device (computer or computer) that is connected to the network has access to a copy of all the information on the blockchain, and in the event of computer failures or a pirate attack, the ledger will be kept secure on the remaining nodes.
Each time a block is filled within the chain, a new block is formed and interconnected with the previous block. Each block has a maximum capacity which we will call: Block size .
The blockchain works with distributed ledger technology and has some elements to guarantee its correct operation. These elements are:
- Time stamping.
- Private key cryptography.
- Data bank.
- Data storage.
- Security.
- Among others.
One of the most attractive benefits that blockchain technology offers us is security and transparency, although this does not indicate that we are isolated from attacks by hackers. In 2020, 2709 cases were found and reported where there was vulnerability (this according to the national institute of standards and technology).
This report tells us that we must take care of our data within the blockchain, and we can do this by making use of immutable tables that protect all our critical business data from being deleted or modified by a hacker. This feature of the immutable tables is of great help for the security of our data. These tables were designed in order to protect our data from possible alterations. The data is organized in different chains and this makes easy access to them difficult.
The stored data receives a unique encryption which helps prevent possible theft. In order to access the information on a blockchain, you must have access to the digital signature to be able to see the stored information. We will call this digital key Hash. This key is of great importance as it will help us protect the stored data from any hacker attack.
In the previous point we mentioned the hash, which is one of the three basic and fundamental elements that a block has. Through these elements, the information stored in any block of the chain can be verified. These elements are the following:
- Data
Data is the content or information that a block stores within the chain. This content is what forms a chain.
The data that a block has has very important information about the sender and recipient. This information shows us details of the amount sent in a transaction, date of shipment, destination of shipment, where the money that is sent comes from and how much the receiver had before sending the money. All blocks have different information from different people and different sources.
- Hash
It is a unique alphanumeric code for each block which is not repeated in any other block. This code is used to represent some block or transaction within the blockchain. This code is the signature or fingerprint of a block, that is, it is its identification. The hash allows us to store our data safely and gives us authenticity. For all this to be possible, very complex logical and mathematical processes are executed.
We use the hash with two basic functions, the 1st is that through it we can protect each block from any attack, and the 2nd is that with it we can verify information about the block.
To give a hash code to a block, it is done through a process called Hashing , which consists of converting any transaction into a verified one. When more data is entered into the block, its code is placed on it. This process ends when the block is full and a new block is created.
- Previous Hash
This hash makes possible the link between the information that is being entered with the information already stored, that is, this hash makes it possible for the chain of blocks to be created. Each block is systematically connected to another and has a unique previous hash.
Once a block is full, a new block is created which links to the previous block. The hash that the previous block has is also placed in the newly created block, it means that we can also see the data of the previous block in the newly created one.
The last hash is also known as the Merkle Root, which is made up of the hashes of all the transactions carried out within the block. With this hash it is enough to verify any information.
First I went to Blockchain Explorer then in the search bar I place the block number that I want to explore.
I chose to explore the 100,000th block of the Bitcoin blockchain. And then I will observe the stored data, the hash and the previous hash:
We are in the presence of the technological age and the blockchain is gaining strength more and more. Understanding how this technology works will give us the advantage of being able to use it correctly and thus adjust it to our needs. It is time to evolve and adapt to the new that Blockchain technology offers us.
Thank you Professor @yousafharoonkhan.
- Professor @nane15