What is Blockchain Technology ? – safaa khadim
“Trusted third parties are security holes.” Nick Szabo (inventor of Bit gold, a precursor to Bitcoin).
Decentralization is the process of dispersing functions and power away from a central location or authority. In a decentralized architecture, it is difficult if not impossible to discern a particular center. The World Wide Web was originally developed as a decentralized platform. Blockchain technologies such as Bitcoin and Ethereum are examples of decentralized architectures and systems.
let’s now explain why : In order to destroy or corrupt a blockchain, a hacker would have to destroy the data stored on every user’s computer in the global network. This could be millions of computers, with each one storing a copy of some or all the data. Unless the hacker could simultaneously bring down an entire network (which is near impossible), undamaged computers, also known as “nodes”, would continue running to verify and keep record of all the data on the network. The impossibility of a task like taking down a whole chain increases along with the amount of users on a network. Bigger blockchain networks with more users have an infinitely lower risk of getting attacked by hackers because of the complexity required to penetrate such a network.
1-Public blockchain : it has no access restrictions, anyone can send transactions or become a validator (for example Ethereum)
5.1-Bitcoin
Bitcoin (₿) is a cryptocurrency. It is a decentralized digital currency without a central bank or single administrator that can be sent from user to user on the peer-to-peer bitcoin network without the need for intermediaries.
5.2-Ethereum
Ethereum is an open source, public, blockchain-based distributed computing platform and operating system featuring smart contract (scripting) functionality. It supports a modified version of Nakamoto consensus via transaction-based state transitions. Ether is a cryptocurrency generated by the Ethereum platform and used to compensate mining nodes for computations performed.
5.3-Bitcoin vs Ethereum
The difference between Ethereum and Bitcoin is the fact that Bitcoin is nothing more than a currency, whereas Ethereum is a ledger technology that companies are using to build new programs. Both Bitcoin and Ethereum operate on what is called “blockchain” technology
A node is a device on a blockchain network, that is in essence the foundation of the technology, allowing it to function and survive. Nodes are distributed across a widespread network and carry out a variety of tasks. there is 2 types of nodes:
6.1.1-Full node : they store the blockchain , verify the blocks , do the mining operation, need a huge amount of storage and computing power.
6.1.2-Partial node : can be used for wallet purpose
In this article i m going to talk about ethereum ;
Blocks are composed of block header and transactions: here is an example of a block in ethereum blockchain : https://etherscan.io/block/8807210
As you can see in the link above the block has a lot of informations let’s explain them :
Block height : it is the current number of blocks that exist in the Ethereum blockchain
Timestamp : indicate when the block was created
Mined by : the address of the miner
Block reward : The total amount of Ether (ETH) given to the address which mined this block. This value includes the total block reward issued by the protocol (it’s now 2 ETH when this article was published) combined with the fees/gas paid by all the transactions included in this block
Uncles Reward: The total amount of Ether (ETH) awarded to the uncle blocks included in this block
Difficulty : the dificulty to mine the block ( approximatly every 12–15 seconds a miner finds a block. if miners start to solve the puzzles more quickly or slowly than this, the algorithm automatically readjusts the difficulty of the problem ).
Total Difficulty : the total mining difficulty of the chain up until this block.
Size : The size of the block file in bytes.
Gas used : (the gas is a unit that measures the amount of computational effort that it will take to execute certain operations) , the gas used is the total amount of gas used by all the transactions included in this block
Gas limit : the total limit of the amount of gas that could have been used by all transactions included in this block .BE CAREFUL when you don’t have enough gas the transaction is canceled but all the gas you sent to the transaction is actually consumed in other words it’s wasted.
Hash : The hash of the block itself using the merkle tree
Parent hash : The hash of the block from which this block was generated, also known as its parent block.
Nonce : A hash of the generated proof-of-work . if you don’t understand it now it ‘s okey we will see it in details in the mining paragraph .
Note:
If you are not familiar with the concept of hash, the important things to know are:
- From a very large departure set (typically infinite and very diverse), a hash function gives back a string of fixed length
- The hash of a block is easy to calculate
- Given a hash, it is impossible to build a message with this hash value
- If you modify the message (even very slightly), you totally change the hash
- It is almost impossible to find two messages with equal hash
Mining is the participation in the validation of transactions that take place in order to confirm all activity in the Ethereum Blockchain. and this is how blocks are added to the blockchain.
7.1-Proof of work :
The process of mining for ethereum is very similar to that of bitcoin mining. Miners utilize powerful computers to make educated guesses about complex mathematical problems. This system is known as “proof of work” (which is a process of maintaining consensus on a blockchain network) because it requires that miners go through the puzzle-solving process in order to receive their ETH reward.
Mining is accomplished by running unique metadata like timestamp and software versions for a block of transactions through a hash function repeatedly. Each repetition alters the “nonce value” (from the last paragraph) which has an impact on the resulting hash value.
7.2-Proof of stake :
Currently, Ethereum uses the Proof of work (PoW) system- this has been the arm supporting blockchain technologies like bitcoin and Ethereum. But Ethereum might not need miners forever, though.
Developers plan to Shift to Proof of Stake( PoS). POS doesn’t require miners to solve complex mathematical puzzles in order to secure transactions, and instead, uses economic incentives to secure network security. The theory is that the use of economic game theory is a better, and more efficient way to maintain network consensus. So the creator of a new block is chosen in a deterministic way, depending on its wealth, also defined as stake.
8.1-Average block time : https://etherscan.io/chart/blocktime
8.2-Average transaction fee : https://bitinfocharts.com/comparison/ethereum-transactionfees.html
8.3-Average gas price : https://ethgasstation.info/
8.4-Ethereum network status : https://ethstats.net/
https://jods.mitpress.mit.edu/pub/7vxemtm3
https://lisk.io/academy/blockchain-basics/how-does-blockchain-work/nodes
https://docs.ethhub.io/using-ethereum/mining/
https://blog.theodo.com/2018/01/deploy-first-ethereum-smart-contract-blockchain/
https://cryptobtcmining.com/ethereum-mining/
https://blockbasemining.com/how-the-switch-from-pow-to-pos-could-affect-ethereum-mining/
https://www.forbes.com/sites/quora/2017/09/14/how-is-ethereum-different-from-bitcoin/#7db83677502b
https://www.coindesk.com/information/what-is-bitcoin
Published at Sun, 27 Oct 2019 18:43:14 +0000
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