Homework on Consensus - Questions

Blockchain and Bitcoin 101
#3455
  1. What does it mean when we say that in blockchain, consensus determine the truth?

The blockchain is hosted on multiple nodes across the network so consensus is when a majority of network nodes agree on the current state of the blockchain. Therefore, the introduction of an illegitimate transaction by a single node on the blockchain will be rejected by all of the other nodes and hence how truth is determined, and trustless transactions are achieved.

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

In a central database there is a single copy of each transaction so there is no way to independently verify a transaction, so trust of the centralized custodian to update the database correctly is used to determine truth.

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#3456

Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    If any singular node in the network disagrees with the rest of the network, the node in disagreement is determined false. Thus in order to falsify the shared ledger one must falsify >50% of the network, which is improbable.

  2. How is this different from how truth is determined in a central database?
    In a central database truth is determined by the central database. Any singular entity with access to the central database can falsify data.

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#3457
  • What does it mean when we say that in blockchain, consensus determine the truth?
    As the example of the yogurt and the cow, everything ,in our single day, has a background chain behind it. Every link do its part and say what it has done. If all the links implicated in that chain agree with that “consesus” it is because its true.
  • How is this different from how truth is determined in a central database?
    The difference is that in a central database, they dont care if a link has done right or not. There is not incentives to be honest. It is just trust and hope that everything is done allright.
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#3458
  1. Well, I think it means, that if the network’s ledgers agrees on the validity of the transaction, then the transaction is verified to be true, and it is added to the network.
  2. In a central database the content is assumed to be true by itself, without independent verification.
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#3459
  1. What does it mean when we say that in blockchain, consensus determine the truth?
  • Being a mathematical way of arriving to a final agreement within a group, consensus in a blockchain removes the need of the guaranty from a middle-autority (either person or institution) and that type of guaranty is replaced by tamper-proof digital records in a distributed ledger. All those digital records represents the truth.
  1. How is this different from how truth is determined in a central database?
  • In a central database, all decisions are taken by a reduced number of decision makers based on their granted authority as unique administrators of the database. This model is highly subjective because it is based on human trust and leaves the door open for data manipulation, corruption, lies and hidden facts. The immutable feature of a final decision taken through consensus in a blockchain certifies the truth.
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#3460

this is the part that made me fall in love with blockchain.

  1. Consensus is being hornost with incentives. Transactions are verified in consent with a Network with financial incentives.
  2. You have to trust the data without verification in advance. Thinking about Facebook and other social platforms how they determine different truths to different people. How can you know that you get the same information as your friends eventhough informations are from a central database.
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#3461

Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth? each transaction is verified by many nodes in decentralized fashion. they are incentivized to tell the truth and not allow bad information in.
  2. How is this different from how truth is determined in a central database? in a central database, it is possible for one bad character to enter bad info, thus the need to hire third party auditors/accountants…with the blockchain, you get transactions and auditing wrapped in one
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#3462

1 & 2 As presented, agreement among many eliminates dependence on the “Trust” of a few, central / centralized narrow the consensus to where consensus has no or the wrong meaning.

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#3463

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    What they mean is that there is more than one party that confirms the true state of a blockchain. What this allows is trustlessness and the confidence that any party in the network can’t tamper with information.

  2. How is this different from how truth is determined in a central database?
    In a central database, it is hard to keep track of large scale business movement and security of information. An individual party may tamper with data which removes the trustlessness. This is a good example of the “Byzantine Generals’ problem.”

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#3464

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    In concept, Truth (with a capital T) is an idea held as fact. In typical cases Truth can be spoken and enter the world by an individual, and it does not actually have to not align with fact. Multiple parties can speak different Truths but there is no certainty that the Truth that contains fact will dominate. Truth via consensus means that all parties have to come to agreement for the Truth to enter the world.

  2. How is this different from how truth is determined in a central database?
    The differentiator that makes Truth via consensus better is that consensus is incentivized to always favor honesty by using financial rewards and punishments. A central database could enter a false Truth without punishment, or in fact receive award by cheating the system. With consensus, the financial cost of sending false Truth is high, while it costs nothing for other parties to catch the lie and in fact they are bound by the shared desire to acquire reward to keep the systems track record honest.

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#3465
  1. What does it mean when we say that in blockchain, consensus determines the truth?

Nodes of information must agree on multiple transactions to come to a consensus that the information is true.

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

Being centralized means that an outside party can manipulate the data entered to appear that what has been entered is true.

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#3466

Answer to Q1: In blockchain, computers in a network need to reach a consensus; i.e., need to agree on what is true and what is not. A transaction is written on the blockchain only after consensus has been established. The decision has not been made by a superior authority but instead, several parties were involved, the issue to be decided upon has been checked by more than one authorized entity.
Answer to Q2: In a centralized database, there is no place for consensus. Truth is conferred from the outside, people trust it because they believe in the trustworthiness of the human actors involved. If they need confirmation, the best way to get it is physically. Examples: If a database says that book xy is in the library, you can go anc check whether it is on the shelf. If you want to confirm that a substance is in fact in your company’s food product, you can send a specimen to a chemical laboratory and order an analysis.

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#3467

Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    We say consensus determines the truth as in blockchain, consensus is the agreement that that a transaction actually took place, or something becomes verified - that it is true.
  2. How is this different from how truth is determined in a central database?
    In a central database, we cannot really know if something happened, only what we are told or shown from that database but as it is centrally controlled, there is no independent way of verifying actions.
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#3468

When saying in blockchain consensus determines truth it is referring to the miners validating transactions. If the miners lie and try to make false transaction they are penalized. Incentives create consensus. All parties or miners must be in agreement before block is finalized.
This is different by being a trustless model, one can look at the records on the blockchain and verify at any time. A centralized source is opaque with the records kept to themselves, only thing you can do is take their word for it.

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#3469

Consensus from multiple machine determinate the truth cause they are incentivated by undestanding what is not truth, what is said by just one machine should be recognized as a “lie” if not shared with the other machine consensus

  1. Central database are different cause they dont share and compare the truth of the information with other database
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#3470

Consensus means that a majority of the network of computers examining a proposed transaction or other recordable event agree on the validity of that proposed transaction or other recordable event. There is not reliance on trust of one or a limited # of individuals but rather the objective mathematical verification by the network of computers incentivized financially to analyze correctly the proposed transactions or other recordable events.

This decentralized system of objective, trustless verification is the opposite of a centralized database where there is no incentive, per se, to validate correctly and where one or a few persons can intervene to incorrectly record transactions. In fact, in a centralized database, there can be a direct incentive to record incorrectly - its called by many names : corruption, embezzlement, collusion… and these problems in a centralized database arise because of the trust requirement.

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#3471

  1. In blockchain consensus determines the truth because when a transaction comes through all the computers on the network need to agree or disagree on what is true or not true before the transaction can be put into the blockchain to say that it is confirmed. All the computers in the network are incentivized to tell the truth.

  2. In a central database one single party can determine if the transaction is true or not without having anybody else being involved.

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#3472

  1. Every party within the network has to agree on all transactions and data-parts. They are incentivized to tell the truth.

  2. Normally truth is determined through trust. We have to trust the party is telling the truth, even though they may not. There is no way to verify as an individual.

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#3473
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    more than 51% of the nodes in de netwerk has the same data
  2. How is this different from how truth is determined in a central database?
    in central database truth is determined by authority
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#3474

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

The consensus mechanism is what makes the provenance of transactions on the blockchain trustless by simply checking whether transactions are valid or invalid before adding them to the public ledger (the network is incentivised to tell the truth in order to come to an agreement).

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

In a centralised data base truth is determined by the individual or institution and is therefore subject to corruption and disagreement.

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