Homework on Consensus - Questions

Blockchain and Bitcoin 101
#743

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Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Blockchains can use different types of consensus mechanism such as Proof or Work (PoW) or Proof of Stake (PoS). These are consensus mechanism protocols that make sure all nodes (device on the blockchain that maintains the blockchain and (sometimes) processes transactions) are synchronised with each other and agree on which transactions are legitimate and are added to the blockchain.

  2. How is this different from how truth is determined in a central database?
    We are talking about Blockchain ledger, a decentralised peer-to-peer ledger as apposed to a centralised ledger which is controlled by an administrator. Blockchains are a ledger that can be written to and verified by nodes on the network, that can’t be amended or deleted. This type of protocol provides the consensus and is a trestles ledger. Whereas, a centralised database has an administrator which can set permission on who has access, levels of control and roles within a centralised database. The administrator can set the security and therefore the trust of the centralised database. In general many databases are run on private networks behind firewalls in data-centres run by large organisations.

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#744

1. What does it mean when we say that in blockchain, consensus determine the truth?
That in order for each block to be accepted in the blockchain, they need to be validated by a number of nodes. These nodes consist various counterparts/computers, that form a huge transparent pool of information, where the truth is determined by collective consensus, resulting in new blocks.

2. How is this different from how truth is determined in a central database?
Centralized databases can easily became victims of outside manipulation, hacking, bribing and many other, truth compromising actions. Central Database therefore always requires some level of trust from its users, unlike a blockchain with its transparency and truth incentivisation.

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#745

Homework on Consensus - Questions

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

  • the set of nodes conforming the blockchain agree upon each other by means of consensus: if-and-only-if all nodes in the network consent (i.e. each general agreement by “unanimity”) on the recorded state of the blockchain transactions then the state agreed up becomes the “new” truth for the complete network.

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

  • in a central database, the latest (visible) state in the database is considered to be the “truth” for the complete system. Each node reads and synchronise its initial state to this central state independently on regular basis. Should the original state be manipulated before reaching a node, this can neither be detected not be corrected. This problem may lead to inconsistent states in the whole network (i.e. independent nodes calculate a new state based on completely different initial state).
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#746

  1. In blockchain the idea that consensus determines the truth means that because all of the computers are working together to verify the information found on the public ledger, any transactions found to not match up with even one copy of the ledger cannot be found to be in consensus with the network. Therefore any transaction that the computers cannot find consensus on over the network is verifiably not a valid transaction, and the network will reject the transaction as fraudulent.

  2. This is different from how truth is determined in a centralized database because there is only one head authority that will determine whether or not a transaction is valid. There is no consensus through multiple minds or platforms in a centralized database, there is only the decision of that one entity or authority.

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#747
  1. Blockchain is decentralized and trustless, for this reason there has to be a way to determine what is true and what is not. In order to do that, the network has to reach a consensus via mathematical proof.
  2. In a central database, truth is determined by the checks performed by the central authority, which may not always have incentive to do that. Blockchain consensus and truth are instead reached in a decentralized way, providing financial incentives to the participants/validators for being honest.
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#748
  1. All nodes on the network agree on the transaction before this is installed on to the blockchain.
  2. This differs as there is one centralized authority that determines what is true and what is not.
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#749
  1. It means that the data that is being analyzed is verified by numerous different networks and if one decides to bluff it will be called out and denied.
  2. You can get away with being bias, bribes can happen
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#750

It means that the truth is determined by comparing the blockchain that is stored on many different computers.

In a central database there is only one place to look for “the truth”, so it can be easily manipulated.

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#751

the truth is determined by all nodes agreeing with each other

in a central data base, the central authority determines truth

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#752

  1. A blockchain consensus determines truth by all parties agreeing on the transaction and the truth is rewarded with incentives . That verifies the authenticity of a transaction because of it was false the network would not record it to the ledger .

  2. It is different because a centralized data base is controlled by one entity or one person . If that one entity is corrupt it can record things knowing they are fake for its sole benefit . With there being no benefit we have to trust these recordings are true .

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#753
  1. Each node in the network (blockchain) must agree with the transaction or consensus is not met and the transaction fails. If there is agreement or consensus than the transaction can take place.
  2. In a centralized database truth is usually checked by auditors.
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#754
  1. All participants have to come to agreement and are incentivized to tell the truth. Thus all participants agreeing (consensus) = truth.
  2. In a central database, you have to trust 3rd parties, and ultimately whoever controls the database determines the truth as no agreement among participants is required.
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#755

  1. You approve an action with the network. This network have the knowledge trough being connected. so lying is not possible because the network will know. So you can prefend fraude.

  2. In a centrale database, it al comes down on one organisation. You have to trust this organisation but they can lying. You don’t know because you can’t verify.

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#756
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus incentives users to be truthful through monetary means.
  2. How is this different from how truth is determined in a central database?
    This is different because the governing parties can be anonymous and truths can be verified instead of going based off of “marketing” terms.
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#757

1 - In order for new information (transactions) to be added in the blockchain, there needs to be a consensus among the parties that verify the authenticity of the blockchain. Thanks to consensus, the blockchain works in a trust-less manner were the majority of parties need to come to agreement for new information to be added.

2 - A central database has 2 main issues: Trust, and Vulnerability. First you need to trust whoever is updating the database, and hope all information are genuine. Second, you are creating a centralized single point of failure that if attacked it could be compromised and not reliable.

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#758
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    consensus trustless incentive determine truth
  2. How is this different from how truth is determined in a central database?
    one authority controls the truth
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#759
  1. In order for a transaction to be added, parties must agree that it is valid. These parties are incentivized to follow the rules.
  2. In a centralized database a single party has the power to define the truth.
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#760

  1. Consensus determines the truth because it is the process of checking the transactions against multiple ledgers on the network determining whether the person sending the transaction actually has the amount being sent.

  2. This is different from determining the truth from a central database because a centralised database is easy to manipulate if someone has access as to where when we use consensus even if somebody edited their personal transaction it will cross it against multiple different databases making sure it is accurate.

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#761

  1. It means that the state of the blockchain record is determined by what all of the participants of the blockchain network agree on. If any of the participants try to lie, the consensus of the rest of the network participants will reject it, and prevent the lie from propagating.

  2. In a central database the state of the records is only reliant on what the central database controller wants it to be.

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#762

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus removes trust. All nodes work together to verify the information.

  2. How is this different from how truth is determined in a central database?
    In a central database, information can be manipulated or changed. With blockchain, companies are incentivised to tell the truth

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