Homework on Consensus - Questions

Blockchain and Bitcoin 101
#2652
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    All participating nodes in the blockchain are incentivized to play by the rules and therefore make money by being honest. Since the nodes are decentralized and each node communicates to all other nodes, there is no way to behave dishonestly because the rest of the nodes will easily tell you are being dishonest and because they want to make money, will act in honest ways so they can profit from the network.
  2. How is this different from how truth is determined in a central database?
    Truth is defined the Database Administrator or anyone who has access to the database. He can modify anything without anyone’s consent. He can always be dishonest.
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#2653
  1. Consensus is easily achievable given the fact that everyone has ready access to the complete information of what has happened and thus it can even happen quickly.
  2. In a central database, the truth depends on what is the latest “version” since there is no access to the history of transactions and changes that have occurred.
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#2654

My answers.

  1. In blockchain, consensus determines the truth by having all blockchain nodes verifying that the transaction/information is true.

  2. Truth determined by a central database may not be verfiable at all.

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#2655

  1. Blockchain replaces the need for trust with a consensus mechanism which uses financial incentives to get a majority to agree on what is true and what is not. These systems make it financially prohibitive for bad actors to inject false information into the network.

  2. In a central database trust is determined by reputation and security. If a centralized database is hacked then its data can be manipulated and is no longer trustworthy…

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#2656
  1. What does it mean when we say that in blockchain, consensus determine the truth? All network computers (nodes) need to agree on a transaction and if it makes sense will be put into the blockchain making the transaction confirmed through consensus.
  2. How is this different from how truth is determined in a central database? The truth is determined by the authority that’s in control of the database and can make changes to it when they decide.
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#2657

  1. Consensus as truth is determined by the fact that the collective structure of decentralized validators are incentived by the network to be honest and to verify each others work as correct.

  2. A central database is managed by a central administrator. The truth is what the admin says it is.

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#2658
  1. What does it mean when we say that in blockchain, consensus determine the truth?In the network or blockchain system by deciding to approve the transaction or rejecting it, in which the decision is made by everyone involved in the blockchain network it determines the accuracy of the transaction is only possible with the fact which is called CONSENSUS
  2. How is this different from how truth is determined in a central database?In central data base the decision is made by the central organization or authority in charge which can be ended up in the fake decision or corrupted aim which is not agreed by a group of people.
    :grinning:
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#2659

Answers:

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    It means through provenance and verification by involving nodes, truth is maintained and agreed upon. Also any node can object the consensus if provenance is not verified.

  2. How is this different from how truth is determined in a central database?
    in a centralized DB, truth dictated by trusting an authority not real time verification. and centralized DB doesn’t use consensus of involved parties (nodes) to maintain the trust.

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#2660

Homework on Consensus - Questions

Q1. What does it mean when we say that in blockchain, consensus determine the truth?
A1. In blockchain, many authorities are providing verification and authentication of processes/transactions on blockchain to maintain genuine records and all authorities agree/disagree on the status/outcome. They are also financially rewarded for their work.

Q2. How is this different from how truth is determined in a central database?
A2. In a centralized database, only a delegated authority has the power to maintain and make changes to the data without any complex reasoning or rules. They are the sole in-charge of maintaining genuine records in the database.

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#2661

  1. It means the decision is not made by an individual but by all the members of the network. In addition it’s an agreement among the members which is verifiable.

  2. In a central database an individual’s decision is enough which doesn’t need any verification so it can be manipulated or removed but in the decentralised database it should be verified and agreed by all the members of the network.

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#2662

1- Consensus determines the truth as the nodes all interact between one another and by these interactions we can guarantee the truth of a product.
2- In a central database one individual determines the truth, and so the truth can be wrong or altered.

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#2663

  1. Blockchain is a decentralized ledger, a database stored on many different computers. Through consensus the different computers agree on which version of the database is the correct on, thereby determining “the truth”.

  2. In the case of a centralized database, the administrator of that database can add or remove data at his will, enabling him to display a rigged, fake version.

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#2664

[quote=“ivan, post:1, topic:8425, full:true”]
Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth?

Blockchain is managed by nodes, each node has a copy of the blockchain and each node determines if a transaction is table to be undertaken by making sure that the instigator of the transaction has appropriate currency to be able to undertake the transaction. The more nodes that confirm that a transaction is able to be undertaken the more consensus we have within the blockchain which then determines the blockchain to have truth.

  1. How is this different from how truth is determined in a central database?

Truth within a central database is based on believing the developer of the database to be truthful, meaning that trust has to be placed within the individual creating the database. With the blockchain it is different it is trustless because of its decentralised nature, meaning that everyone/node has to agree that the decentralised data is true and then it can be believed to be so, due to consensus.

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#2665

What does it mean when we say that in blockchain, consensus determine the truth?

  • The network as a whole (majority) validates and determines the validity of a transaction. This is accomplished by science and math, not humans.

How is this different from how truth is determined in a central database?

  • central authority can do as they like (kind of) and behind closed doors.
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#2666
  1. A group of nodes reach to the same outcome in a trustless way
  2. From a group centralized databases, you pick one source of truth and you try to ensure that It won’t be compromised, the rest trust blindly what that central db states.
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#2667
  1. There is incentive to say the truth inherently in the network, if you do not you are penalised instantly !
  2. In a central database, the truth goes up to the extent that you trusts the administrators that they have not modified the database / giving you access to the right copy in case of an audit
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#2668

  1. The network of computers all have a copy of the database. All the computers on the network need to agree or reach a consensus on the data by verifying it. This consensus determines the truth.

  2. In a central database you have to trust what the controlling authority tells you is the truth. Only one computer providing the info as apposed to a network of computer all with a copy of the same database.

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#2669

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    In blockchain, multiple network nodes are required to confirm using a set of rules, that the transaction is valid, for it to be accepted on to the blockchain.

  2. How is this different from how truth is determined in a central database?
    In a central database, the truth is determined by what the whoever has control of the database. This information has the potential be manipulated by someone given the right incentive.

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#2670
  1. Network consensus is what permits a new transaction from entering the blockchain. What’s in the blockchain is now accepted as truth.
    2 Versus a centralized blockchain where the truth is determined by one company or one person - requiring a lot of trust in this person/ company (not trustless).
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#2671

1. What does it mean when we say that in blockchain, consensus determine the truth?
In blockchain we want things to be true, not simply trusted.
Blockchain, being distributed and decentralized, needs to verify several times the same information, and having tons of copies of the same database, we don’t risk to lose data.
With this method every movement or transaction is verified several times by different computers that can communicate and compare, giving or not giving the ok to the transaction. If they agree they give the consesus to that.
When the blockchain valuates something, partecipants are payed for that, so tell the trut is financially convenient.

2. How is this different from how truth is determined in a central database?
In acenral database we have just one copy of the data(maybe a pair of backups) and a single entity of control, tht can be wrong, or corrupted with money or hacked. So a cantral DB gets trust, not truth.

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