Homework on Consensus - Questions

Blockchain and Bitcoin 101
#663
  1. it means that every nodes takes part of an agreement.

2.in a central database you ha to trust someone else, a decentralized database is trustless because of consensus

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#664
  1. What does it mean when we say that in blockchain, consensus determine the truth?
  • On the blockchain nodes will cross check with each other to ensure each blocks match, and that funds are immutable. This means that fake transactions canā€™t be slipped in, or false information cannot be added to the network unless the thousands of other nodes agree.
  1. How is this different from how truth is determined in a central database?
  • In central databases it can be costly to audit every point in the supply chain. You can have centralized databases come to a consensus at one moment in time, but with human nature that consensus can be broken the next day unless continuously checked. Ie, making sure clothing isnā€™t inclusive of child labour, ensuring food products donā€™t use added contaminants, or gold isnā€™t collected from protected nature reserves. Humans give in to greed and become complacent with turning a blind eye. So long as humans have control over centralized databases information can be manipulated.
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#665
  1. Consensus means that multiple entities have verified the information and determine that it is correct .
  2. In a central database any single person can decide what is stored on the database.
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#666

  1. On the blockchain there are many, many computers which validating the same content. When everyone says it is the truth, then its validated.

  2. On a central database there is one authentity which says that it is so and we have to trust this authentity that this is the truth. No one else is validating the content.

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#667
  1. Consensus determines the truth because it is built on top of the incentive to only back the truth
  2. Through the decentralized power of concensus in a blockchain while an authority can intervene in a central database
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#668

  1. block chain reaches consensus when all the nodes come to agreement on a particular path problem

  2. in a central database the central authority decides what is true and what is not

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#669

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    It means that the valid data is the one that is verified by most of the nodes in the network, through a consensus mechanism.

  2. How is this different from how truth is determined in a central database?
    In a central database we need to trust the ā€œadministratorā€ of the system. In a blockchain consensus is achieved in a decentralized manner without having to trust a single party.

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#670

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Due to the decentralization of the network, there are many entities (computer) being able to verify the transaction(s). They all have the same database (leger), allowing to uniformly approving or disapproving a new transaction

  2. How is this different from how truth is determined in a central database?
    A central database allows in the worst case one single person to determine the truth. In an decentralized network on the contrary there are all the different nodes which need to agree to a uniform decision. Donā€™t tust, but verify.

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#671

  1. Consensus determining the truth refers to having multiple participants of the blockchain agreeing that a particular participant has made a transaction that makes sense according to their latest update of the database.

  2. On a central database, truth is determined by one participant, usually the owner, or a select group of participants and could make reservations arbitrarily on certain transactions. In other words, it is not true consensus, but rather a permission based system.

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#672

  1. Consensus is when the computers all agree that a transaction has been made, if only one computer agrees it does not go in the blockchain.

  2. In a central database only one person decides the truth so they can easily manipulate it.

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#673

In blockchain, all the computers in the network have all the history, and they all must agree a transaction is true.

In a central database, a central figure decides whether to trust a transaction.

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#674

  1. The blockchain (information) is stored on a network of computers, each having a copy of it. When new information shall be added to the blockchain, the network first has to make sure, that the information is true. When this happens, the network has reached consensus about this information considered ā€œtruthā€. Only then it is added to the blockchain persistently.

  2. In a decentral database, only one entity decides, what is ā€œthe thruthā€. This makes it much easiers to store information, that is not true.

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#675

#1. Transactions needs to be confirmed in blockchain, which means the transactions gets verified.
#2. The central database can add or not add, what ever they like.

#676
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    The block chain network collectively confirms the truth through all blocks and nodes achieving consensus.
  2. How is this different from how truth is determined in a central database? In a centralised data base data can be altered or manipulated by the central authority.
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#677
  • What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus means that a network of nodes all agree that a transaction is true and correct, validating it and updating the Blockchain
  • How is this different from how truth is determined in a central database? In a central database thereĀ“s only one party who verifies the transaction, making it vulnerable to corruption and basing it its validity on trust only.
    [/quote]
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#678

[quote=ā€œivan, post:1, topic:8425, full:trueā€]
Homework on Consensus - Questions

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

Consensus is a mechanism to ensure transactions/data are valid without the need of central authority and prevents double spending.
Network of computers/participants also known as Nodes will reach Consensus based on Provenance and reject the untrue transactions.
Essentially Consensus removes the need of trust and be confident to reach the truth not because of trust but because we can check and verify the blockchain network.

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

In a central database, the truth is determined by a central authority top management. On Blockchain Truth is determined by consensus, where the participants of the network need to agree whether a transaction is valid or not .
Unlike central database who can manipulate the data, on Blockchain Consensus is crucial for a Trustless system and by design it is built on incentives to financially reward all participants(miners) to tell the truth.

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#679

It means that the majority of the nodes connected to the network have verified and approved a transaction/claim thus asserting its validity. The blockchain does not care about opinions; it cares about facts.

A central database is ā€œcentralizedā€ aka controlled by one entity/small group of entities with a common goal, which not always is telling the truth; therefore, making false statements more likely to surge and appear to be true, even if they are not, if these benefit the entity/ies.

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#680
  1. It means that a number of independent nods need to agree on the verification of a transaction.
  2. Independent verification that can not be altered by any one entity.
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#681

  1. It means that the majority of the group comes to an agreement on the network.

  2. Because is base on one place only and canā€™t be audit by other people except the ones of that company only.

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#682
  1. The network is in agreement that the transaction is valid.
  2. Because there is no consensus in a central database we cannot verify the validity of the transaction.
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