Homework on Consensus - Questions

Blockchain and Bitcoin 101
#4520

Consensus is when different algorithmic calculators can confirm one transaction, then it means it is true and a real transaction reaffirmed by all.
In central databases the transaction is recorded on a master computer which records a credit and debit ledger which has to balance.

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#4521
  1. There needs to be an agreement between the computers in the network that the txs is correct. The miners are incentivized to be honest by earning money and that way we know it is the truth. If no consensus, no transaction.
  2. In a normal database there is only subjective truth.
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#4522

  1. The network need to attaint consensus before allowing a transaction to happen. Every nodes agree that the transaction make sense. That the money that is spend is there. So if someone “create” Bitcoin out of thin air somewhere and try to add it in the Blockchain the network will see that no one have ever send Bitcoin there. So it will ignore it. The Network will attaint consensus that that transaction make no sense.

  2. For a centralized database, there is only one copy of that database if something change we cant really prove that it should be something else. The truth is what that database show. If someone change it it is what it is.

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#4523

  1. What does it mean when we say that in blockchain, consensus determines the truth?
    The majority of nodes need to agree to the veracity of submitted transactions in order for the transactions to be confirmed and accepted by the network.

  2. How is this different from how truth is determined in a central database?
    Whatever the trusted/controlling entity says is the truth, is taken as the truth.

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#4524

  1. Consensus determines the truth because all the computers in the network need to agree on the decisions being made.

  2. This is different from how the truth is determined in a central data base because there is no central authority that controls it. Every node has to agree that the transaction is the truth to get added to the blockchain. In a central database the controlling authority can add whatever they want on there own.

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#4525

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

Because it is due to consensus of the whole network that validates an event. Without consensus of the whole network, an event will not be written on to the blockchain that is the truth

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

In a central database, the truth is determined by one party which controls the whole database. In a central database, a power of truth is determined by singular entity but in blockchain, the whole network needs to agree to be the truth.

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#4526

  1. When a piece of data is put into the blockchain, it means that it has been approved by all the nodes, so basically there was a consensus among the different nodes. Since all the nodes are financial incentivate to tell the truth and make a correct evaluation, all information in a blockchain is very likely to be true.

  2. A central database is centralized, so basically it can be controlled by one or a few entities that can manipulate data into the database however they want, so a piece of data is confirmed and put into the databse by people who are not incentivate to tell the truth.

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#4527
  1. Because all the computers in the network have to agree or disagree.
  2. Consensus is determined by mathmetical equations vs. believing in the organizations that produce products for us and that they are manufacturing what they say they are producing.
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#4528

Consensus in the supply chain makes it harder to cheat when all parties are communicating and verifying the product and it financially rewards honest parties that play by the rules.
In a central database truth is based on trust in an unverified, less traceable, more corrupt-able system.

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#4529

What does it mean when we say that in blockchain, consensus determines the truth?
the truth is agreed between all block entities

How is this different from how truth is determined in a central database?
Truth is determined by a centralized entity

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#4530

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    That all nodes come to an agreement if a transaction is valid or not and if or not a transaction is confirmed.

  2. How is this different from how truth is determined in a central database?
    Truth is determined by a trustless system that creates incentive for acting honestly because all information is shared in the supply chain network. Where in a central database there is room to be opaque because of the lack of verification an actor is acting honestly.

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#4531

Continuing the discussion from Homework on Consensus - Questions:

  1. What does it mean when we say that in blockchain, consensus determines the truth?
    All the nodes must agree on the transaction history. The blockchain allows more than one authority to verify that a transaction is correct.
  2. How is this different from how truth is determined in a central database? In a centralized system there is usually only one system that veryifies the transaction. You have to trust that the central authority is correct.
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#4532
  1. What does it mean when we say that in blockchain consensus determines truth?

On blockchain, consensus determines truth because all nodes must collectively agree the data is valid before including it on the blockchain. Should one node disagree about the data validity, concensus was not reached and the data is excluded or concluded as being false. The most common consensus algorithms inclued Proof of Work (PoW), Proof of Stake (PoS), or Delegated Proof of Stake (DPoS).

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

In a centralized database, there is a single source of truth (SSOT) where aggregate data can be edited in one place. One person with authority can manipulate the data in such a way that it is considered invalid or not true. On the blockchain, the data is immutable, relies on a consensus algorithm, and therefore is accurate and valid. Since the blockchain is decentralized, it is the most reliable source of truth.

2 Likes
#4533
  1. All the computers in the network have to agree that a certain transaction is legit and accept it.
  2. In a central database truth is based on trust on a single company / institution / organistion etc
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#4534

What does it mean when we say that in blockchain, consensus determine the truth?
Consensus in blockchain determines truth by having multiple parts in a network all information is true

How is this different from how truth is determined in a central database?
Truth is determined in a central database by an authority making the decision on what’s truth and making the changes, blockchain can not be changed by anyone.

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#4535

  1. It means that every node in the network needs to agreed with the information in one transaction in order for this one to be processed

  2. In a central database the transaction is approved by whoever runs it. This means that the info can be wrong but the transaction goes through if someone modifies some info in the database.

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#4536
  1. In blockchain several nodes will validate the transaction before it gets accepted/recorded in the block. It does not simply insert records/transactions without validation.
  2. Using central database we simply trust the system that inserts records in the database to be doing everything correctly.
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#4537

  1. By having multiple computers in a network each storing a copy of the database (nodes), truth is only the information validated by all of them.

  2. In a central database there is only one version of the information, it cannot be compared or verified.

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#4538

  1. What does it mean when we say that in blockchain, consensus determines the truth?
    Consensus, or the network of computers agreeing, on the integrity of a transaction results in confirmation, thus verifying and recording truth.

  2. How is this different from how truth is determined in a central database?
    It is very interesting in the Cows to Yogurt example - the consensus becomes all the different players supplying good to suppliers and the network of integrity inherant to the blockchain … you cannot cheat! If you make a claim, it is very easy to prove (or disprove) relative to traditional methodologies. Easier traceability!

    Blockchain consensus is reached through incentives. Computers are incentivized to tell the truth by either confirming the transaction or revealing it as false and not allowing it in the blockchain.

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#4539

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    When parties on the network confirm a new transaction is legitimate. If they do not agree then the new information is discarded.

  2. How is this different from how truth is determined in a central database?
    In a central database an individual has authority to determine truth instead of the entire network who has incentive to be honest.

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