In blockchain the truth is determined by not one, but all the computers in the network.
In a central database system the truth is arrived at by the the system controller.Whereas,in a blockchain the truth is verified by multiple nodes in the system.
It means that any given transaction or record is verified by several sources. Not any single entity.
This is different than from a central database because in a central database there is trust involved that the single entity is being honest and transparent with their record or transaction.
Every transaction to the network must be varified by each participant of the network
each participant is incentivized financially to tell the truth
In a central database you have one authority that is verifying the truth (for example the bank)
Not every network participant is incentivized by telling the truth.
Consensus means that everybody in this blockchain is convinced that the facts are right in this transaction.
In Blockchain it is not only person who tells you whats true, but the community
In blockchain, when you say that consensus determines the truth, it means that all nodes on the blockchain are agreeing on a mutual thing simultaneously. This process removes the need for trust, and uses verification instead by incentivizing the miners to play by the rules; if something can be verified, there’s no need for trust, which is why consensus determines the truth.
In a central database, the truth is based solely on trust, and cannot be verified. This leaves room for manipulation and dishonesty.
One cannot double spend, if balance on his wallet does not exist.
Consensus removes trust.
It means that in blockchain, which requires nodes to validate transactions, there must be a majority of them that agree on the validity of a transaction before adding it to the blockchain. This is why it is said there must be consensus, and consensus determines the truth rather than having to trust someone or something.
In a central database, rather than relying on validation from the majority, you rely on a central authority to determine the truth and therefore you need to trust them.
A: Because blockchain is a decentralized network, a transaction is only added to the database once it has been verified by all nodes. If a transaction cannot be verified through the node-consensus process, it cannot be verified as “true”, and cannot be added to the blockchain. Therefore, anything on the blockchain must be true.
A: In a central database, the “truth” is whatever the central figure overseeing that database determines it to be… regardless if others can find fault in the data.
Homework on Consensus - Questions
Consenses - All of the nodes of the blockchain validate (or decide if they are valid) all of the transactions and all have incentive to to it accurately.
In a central database, truth is determined by the controller or controlling parties and can be altered or manipulated. In Blockchain - it is determined by verification and can not be altered or edited. The truth is determined b all the computers!
Blockchain, consensus determines the truth becouse the decision for the confirmation is given from decentralized computers in the network (which are incentivized to tell the truth), that they prove mathematically that data (transaction) is true.
In a central database there is an authority that control the data and we cannot check and verify that the decision that was given is true.
Homework on Consensus
1. What does it mean when we say that in blockchain, consensus determine the truth?
This means that because the network is incentivised to tell the truth, the consensus made regarding any transaction is verified and objective across multiple nodes that are all in agreement. This makes it impossible to cheat the system, eliminating the need for trust and therefor leaves no room for doubt.
2. How is this different from how truth is determined in a central database?
At the rate we are going now, “truth” as it seems in the centralised database, is highly subjective. This means that it is truth (or considered as truth) based on the call of the governing body or authority who says that it is so and all you can do is trust them. It may also be altered or amended at any given time with all record of it wiped and never to be recovered. Therein lies the simple yet devastating systemic flaw of the centralised database.
Because blockchain is a system of computers/databases, all computers must come to a consensus or agreement when verifying a transaction. Therefore, if a consensus about a certain transaction determined it was an in correct or false transaction, then that will be the truth upheld in the blockchain.
In a central database, only members/computers of the central party come to a consensus about whatever. In blockchain, there is no central party, all computers participate in the consensus.
Q: What does it mean when we say that in blockchain, consensus determines the truth?
A: If a new information comes into the database of the blockchain, a network of computers verifies if the new input information makes sense or not. They reach a consensus through incentive. The network of the computers of the blockchain are incentivized to tell the truth itself. What might drive people to consensus with this system and to get full transparency is money.
Q: How is this different from how truth is determined in a central database?
A: In a central database you can put an information and no other has a say if it can be verified or not. The institutions or corporations that use this kind of information can interfere and you have to build trust to what they say and you cannot verify it sometimes.
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A blockchain is composed of nodes , which are individual computers connected to other computers on the blockchain network from which they acquire a copy of the blockchain. These computers can be your laptop, cellphone, a server, or any computational device with access to the Internet. Therefore, instead of relying on one central computer , whose data can be easily altered by one central authorized individual or lost due to natural catastrophes , the blockchain network rather depends on nodes coming to a collective agreement. Technically speaking, they form a consensus in order to determine the truth everytime either a new transaction is being executed or new blocks being included to the network by miners. A node cannot lie since it is programmed to follow incentive rules, and if all nodes that are online come an agreement that new information is valid or invalid, they will store and update information accordingly to these incentive rules. Futhermore, a blockchain only needs one node to update all information if let’s say all other computers end up being offline due to several external factors (e.g. natural disaster, a government banning cryptocurrency, a power blackout, an E.M.P., or the God of Sun punishing humanity and setting us back to pre-electric times, etc…). Once they go online again, they will immediately receive the same copy of the blockchain from that one node that remained alive on the network during that harsh period. In short, it is very invulnerably secure unlike centralized computers.
Benefits: Blockchain experts forecasted that there will be decentralized voting network that can be utilized to ensure fair elections and prevent riggings. I really hope this gets adopted by all democratic countries. Soon, we as human beings with the right to vote on our smartphones will become real-life nodes in democratic elections. Result: Trust is not required due to Transparent and Immutable vote counts !
In conclusion, due to Blockchain having this unique feature called Consensus, Blockchain is not only essentially beneficial to store and move cryptocurrency safely, but it can be utilized for non-monetary practices as well; such as group decision making by all individuals in order to contribute to better quality outcomes which benefits and empowers the community as a whole as well as making decisions towards a positive future without the fear of the occurrence of interferences.