Because every computer in the network has to agree to the information being true.
In the a central database the information has two be validated by some logic a programer put in and he could leave loopholes.
What does it mean when we say that in blockchain, consensus determines the truth?
All the nodes on the network must agree, or come to a consensus about the data being true or false. This is another feature trustlessness. Consensus creates provenance.
How is this different from how truth is determined in a central database?
A centralized database does not have a distributed node lodger to check itself for data validity.
That every single PC connected to the worldwide network that makes Blockchain possible, arrive to the same conclusion verifying that the uploaded data is correct.
Truth determined in a central database is based in trust.
Truth determined in Blockchain is verified looking at past data
For a transaction/data to be accepted into a blockchain consensus must be reached across all nodes in the network i.e there must be agreement across all nodes about the incidence of the transaction or data. i.e no one entity/person can manipulate the data entry.
If an action did indeed happen, then it must be verified across the entire network. If there is incongruence, that raises a question mark about its validity.
How do we ensure consensus? : Through financial incentives for each node.
You literally receive money for telling the truth.
1. What does it mean when we say that in blockchain, consensus determines the truth? Because for there to be ‘consensus’ i.e acceptance of data onto the network, all nodes must be in agreement.
2. How is this different from how truth is determined in a central database?
Transparency : Truth in a central database is determined by a single entity or central authority within which ‘verification’ power is vested.
Hey @DrChops, I like the way your phrased this 'A central database is in the hands of the entity that owns the data. That entity itself or owner can manage, edit, delete, add, manipulate the data amongst other things.'
don’t trust - verify. If verified, it goes on the blockchain.
peer to peer vs bankers in control
Homework on Consensus - Questions
What does it mean when we say that in blockchain, consensus determine the truth?
It means that the trustfulness of the information provided in a blockchain relies on the validation process by the network of computers, which are incentivized by their economic interest. Thus consensus is achieved not by trust but by verification.
How is this different from how truth is determined in a central database?
A central database would not have any requirement of agreeing to the validity of its information by any group of people, thus information could be corrupted.
all the validators have to agree on what is true. Once written on the blockchain, the agreed upon truth is then accepted and immutable.
in a central database the curator decides what is true, and the records are curruptable and can be modified
Answer:
Consensus is the ability to make a decision in a network transaction whether an action is true or false. If the network agrees a transaction is good it gets added to the ledger and if the network finds it to be false it gets discarded.
In a central database a single copy database copy or single individual chose what is truth. If the database is corrupted then truth is altered.
1 all the computers in the network must agree before changes canbe made.
2. in a central database one person can have authority to make changes
1.)It means the network of computers must agree and verify that a transaction is true.
2.)In a central database we rely on the idea that parties are telling the truth. We rely on trust not data.
What does it mean when we say that in blockchain, consensus determine the truth?
It mean that all decisions are being made together through a decentralized computes network, all decisions are being double-check all decisions about what information is present and what information is not present are being made with consensus of many entities.
How is this different from how truth is determined in a central database?
In a central database truth is determined by one entity and no one else has anything to say.
Because all processes and agreements in the network are declared to be true and it can therefore be checked.
In a central database, someone can manipulate an entry and it is not verifiable.
In blockchain when a decision is made it has to be agreed by the other party members and it has to correspond with all the other notes.
In a traditional database decisions are validated by a single party or entity so the information can be corrupted, modified or lost. Non of this could be intentional. Compared to a decentralized database where any modifications or any information added is verified and mirrored by other network participants and notes.
In blockchain when we say that consensus determines the truth we mean that decisions are not made by trust, but by verification by a group of people. There is trustlessness in blockchain decisions.
In the blockchain, there is a network of computers that have to agree if a transaction makes sense, or not before this information is added to the database. By verifying if the information is correct everyone makes money. Provenance cannot work if consensus is trust, the information has to be verified in order to make money and this is not the case in a central database.