Homework on Consensus - Questions

Blockchain and Bitcoin 101
#5123
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    It means that all participants must verify & agree for a transaction to be accepted onto the blockchain.
  2. How is this different from how truth is determined in a central database?
    In a central database only 1 user has to agree for a transaction to be verified & accepted. All participants are in affect controlled by 1 central point.
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#5124
  1. Before a transaction can be added to the blockchain multiple “consensus nodes” have to agree the transaction conforms to the logic of the network.
  2. Database records are single user first in wins and locks the record.
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#5125
  1. Truth in a central database is determined by a central authority.
  2. It means that the truth is decided and agreed upon collectively by the people.
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#5126
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    It means that the data has been verified by multiple sources that have all agreed the data/info to be correct.
  2. How is this different from how truth is determined in a central database?
    In a central database the data is not verified by multiple sources so the “truth” or data maybe incorrect or manipulated.
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#5127

  1. consensus means all of the other nodes must agree to validate a transaction.

  2. this is different from a central database because it requires multiple nodes to respond and verify.

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#5130

Consensus is the financially incentivized activity of network participants to confirm the status of every single transaction. If a transaction is seen as valid by the network participants, it will be added to the chain and if the network finds it to be false it will be excluded.

In a central database a single copy or single party determines the truth. The database could get corrupted and the facts changed.

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#5131
  1. What does it mean when we say that in blockchain, consensus determines the truth?

Consensus is about agreeing things. The things we agree in blockchain we can verified. If the truth has been verified as trustworthy by each computer’s ledger , which is part of the network, The transaction is can then be agreed. Or rejected if the transaction is verified as not trustworthy.

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

Central database is centralised , and then we need to rely on a single authority to trust the transaction to be truth. It is based on trust and no verification that the transaction is what it says it is, is done because we can not verify the (public) ledger.

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#5132
  1. consensus means agreement between the node verifiers in other words multiple third party verifiers are in agreement. The mathematical equation must match or it is invalid.
  2. Central databases have no such redundant self-checking veracity like block chain. A corrupt central database has no reference or checks and balances.
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#5133
  1. Each node in the network comes to a consensus because they each have a copy of the blockchain. If one of the nodes tries to alter the blockchain, all the other nodes will not be in consensus and therefore the data that node is providing can be clearly verified as a lie.
  2. In a central database, truth is determined based on trust and accountability to the organization distributing the currency and/or mediating transactions.
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#5134

1 When we say that in blockchain, consensus determines the truth it means that all the computers that are part of the blockchain network need to agree in what is true and what is not

2 In a central database there is only one centralized source of truth

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#5135

  1. We mean we can trust group consensus mechanisms to pursue the financial incentives that promote truth of information over false information, as determined by the wider group.

  2. in a central database there is neither access nor incentive to verify the inputted facts at the group level, usually involving separate parties, but not always.

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#5136
  1. Consensus prevents somebody to cover information, since everyone has access to the same data level
  2. Truth means that we can’t see the data itself, but rely on someone else to interpretate it
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#5137

Consensus determines the truth in blockchain. This means there is a multitude of computers needed that are incentivized to tell the truth, that validates with others in the network and provides no accidental loss.

The truth determined in a central database is in trusted because of ownership and location is singular. This allows for corruption within deciding the truth in their favor.

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#5138
  1. What does it mean when we say that in blockchain, consensus determines the truth?

In blockchain the nodes in the network have to deside if a transaction is valid or not. If it is they’ve reached consensus, if not the transaction will be ignored because there is no consensus.

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

In a central database there is only one party who can approve things. Which you have to trust for its outcome. With blockchain it could be all verified.

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#5139
  1. What does it mean when we say that in blockchain, consensus determine the truth?

Because the network is made up of independent nodes all working towards the same end (a decentralized network of transparency and accountability); it only takes one node to disagree and disapprove a transaction. Consensus across the network means many sources agree about something important, which creates a transparent record… of truth.

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

If only one or a few people can change or alter a centralized database, those few people have less accountability and transparency. As a result you have to trust that one person implicitly that they have maintained truthfulness at all levels, and that trust is substantially reduced when they could change it at any time. Truth is whatever that one person says it is, as opposed to thousands.

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#5140

Blocks cannot be added to the chain or modified without a majority of nodes coming to a consensus that they are legitimate.

You need to trust the owner/operators of the central database to be honest. Once the master record has been altered, there is no way to recover the original.

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#5141

1, It means that all nodes on the blockchain network have checked and verified data in question.
2. Central database is not connected to other databases that will verify said data.

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#5142
  1. What does it mean when we say that in blockchain, consensus determines the truth?

In a decentralized network like blockchain, consensus algorithm is applied as a way for the individual nodes to communicate with each other and to come to an agreement regarding which new data to (not) add to the database. Nodes are incentivized to tell the truth (verify correctly whether new data is true or false) because they receive (monetary) rewards for being honest and because other nodes can also verify the validity of new data. Thus, consensus creates a trustless environment because agreement is reached based on verifiable information and not based on trust.

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

In a central database truth is determined by a single party, the owner of the database. However, the owner may manipulate the data and for an outsider it may not be possible to verify whether the presented data actually represents the truth or not (in case the outsider does not have access to the data necessary for the verification of the truth). In such a case truth is based on trust.

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#5143

  1. Consensus means that people agree on something that is true, its more of a democratic agreement rather than trusting what only one person says is true.
    Miners for example agree that a transaction is true and puts it on the blockchain, if they don’t agree its true (lets say i try to transfer 1000 BTC to myself) they decline it, not a verified transaction.

  2. Because in a central database, the truth can be altered by one authority. Let’s say your information in this database was being sold by this authority, all they have to do is say ‘’no it’s not being sold :)‘’ And you would have to trust that.

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#5144
  1. Consensus determine the truth because multiple parties where involved in verifying the transaction. It incentives and rewards honesty.
  2. In a central database, the only party that verifies the transaction is the one producing it. Leaving full control to that said company to dictate the transaction.
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