Homework on Consensus - Questions

Blockchain and Bitcoin 101
#2632
  1. What does it mean when we say that in blockchain, consensus determine the truth?

When a transaction happens, it is neccesary that a big mayority of the computers that take part in the verification will consider this transaction as safe and real. This way, the verification is not made just by an individual, what makes this process way more reliable

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

In a central database, often it is impossible to verify where the things came from. You have to trust because it is difficult to verify. Furthermore, a single individual decides if the transaction is real and safe.

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#2633
  1. What does it mean when we say that in blockchain, consensus determine the truth?

Consensus determines the truth means that a decentralized network of nodes comes to agreement about transactions.

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

This is different from truth in a central database because the sources of said truth are decentralized and can be verified externally.

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#2634
  1. That a descentralized system has made the decision.
  2. A central database makes a decision on its own, so we have to trust it.
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#2635

  1. Because consensus is verified by math and is trust-less.

  2. Centralized databases are controlled by individuals you have to trust. Not trust-less

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#2636

Homework on Consensus - Answers to Questions

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

When a transaction comes in, each computer in the blockchain network must decide if it makes sense or not. In order for a transaction to be accepted and included in the blockchain database ledger, they all have to agree by consensus that it is valid. Since everyone on the network has a copy of the ledger and can communicate with everyone else, it is very difficult to cheat. If one company says one thing, but everyone else says that isn’t so, there are no transactions showing that, then the transaction is rejected.

Here’s an example: A company says it is adding high quality cane sugar to yogurt. The suppliers say they only provide high fructose corn syrup to that company. There are no transactions showing the company obtained good sugar from anyone. Therefore the claim the company is making will be shown to be untrue.

Consensus ensures that trust is not needed. Each transaction is verified and agreed upon by all in the network. It is difficult to cheat. The incentive to make money keeps people honest. Good transactions are accepted and included in the Blockchain; fraudulent ones are rejected.

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

A centralized database is under the authority of a single administrator or company. That entity can add, update, and delete records. This can include adding fraudulent data, changing data to be false, and deleting evidence. There is no check that the information is true or the records honest. Other companies have to trust what the company says. There is no providence, no consensus, and no outside incentive to be honest.

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#2637

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Several different computers muat agree (reach a consensus) that the data input is correct.

  2. How is this different from how truth is determined in a central database
    In a traditional database, one central authority validates the data input. In a central database, data can also be moved, deleted or tampered with - this is not possible in a decentralized database where all the inputted data is permanent

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#2638

The truth in a centralised data base is not verified by the majority before being accepted as legitimate.

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#2639

  1. Blockchain participants are incentivized to tell the truth, which can be verified without trust.

  2. In a central database, participants are required to trust that the provided information is accurate. However, central database providers may not be incentivized to be truthful, which can hurt other participants.

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#2640
  1. The blockchain has a method of providing incentives to the decentralized users to verify the truth of each transaction in it, so this acts as a self-enforcing mechanism to verify facts.
  2. The blockchain, being decentralized and providing incentives to verify the truth of data, differs from a centralized database because a centralized database can be easily altered and tampered by the central authority. The blockchain is thus more accurate and reliable, which allows people to enter transactions more readily.
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#2641

Continuing the discussion from Homework on Consensus - Questions:

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#2642
  1. It means that all the computers in the network must agree for something to be true on the blockchain.
  2. On a central database, you only need the central database to aggregate everything, but that does not mean that all the computers feeding the central database are telling the truth.
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#2643
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Any data that is to be added to the blockchain must first be verified by every active node that is running the blockchain i.e. there must be a consensus amongst all nodes in order to add data to the blockchain. All nodes are financially incentivized to record the truth thereby eliminating the need to “trust” in validity of the data.
  2. How is this different from how truth is determined in a central database?
    In a central database, there is only one central authority that verifies data and records it. The validity of the data is thus dependent on the trustworthiness of the central authority.
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#2644
  1. it means the transaction is verified by everyone before the transaction is allowed.

2 a centralised system does not need any consensus so information has to be down to trust of the centralised company.

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#2645
  1. Truth is determined by the consensus of many independent nodes on the network, all verifying transactions are correct and can be added to the blockchain. Economic rewards are used to ensure the nodes ‘tell the truth’
  2. Truth can’t be determined from a central database, only that the provider is trusted to provide true data and is controlled by a central authority
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#2646

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    In blockchain, each node confirms each transaction. So there is no single transaction stored on the blockchain, that the majority of nodes didn’t verify and agreed that it is valid.

  2. How is this different from how truth is determined in a central database?
    In a central database, a single entity can change or delete information, without the need for approval of anyone else.

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#2647
  1. because when everybody knows where each thing come from, its hard to cheat
    2 You dont have to trust, you can just verify because there its a record
2 Likes
#2648
  • What does it mean when we say that in blockchain, consensus determine the truth?

It means since the networks of computers works in agreement (decentralized) by keeping copies of all transactions carried out, it becomes difficult for anyone to doctor the system or blockchain because it operates in a trustless manner.

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

In a typical central dbase, the system is not decentralized hence there is the constant need to frequently provide oversight. In this way, the system can be doctored from time to time which can lead to the introduction of bias and false information.

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#2649

1.What does it mean when we say that in blockchain, consensus determine the truth?
A. Minors have a finical incentive to be correct because they destroy energy first and get rewarded only if they are correct. When enough Nodes accept the block then that is consensus and that block is truth, it can not be changed in the future.

  1. How is this different from how truth is determined in a central database?
    A. Humans can make errors, change their mind, or be forced to change or destroy data. Whenever data can be change it runs the risk of being changed. If there is no way to change it even if someone wants to that is the only way to have true untouchable censorship resistant data. Double think can not happen on Bitcoin.
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#2650

Bitcoin is a decentralized, transparent network that allows everyone to track all expenses and transactions made world wide at any time

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#2651
  1. What does it mean when we say that in blockchain, consensus determine the truth?

Consensus means that different validators have decided what gets added in the blockchain, what datasets. It means the “truth” is not decided by a central party, is not centralised, but it is decentralised by the consensus mechanism. All the economic incentives are aligned so that the consensus mechanism seeks the truth and sets it in the blockchain.

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

It should not be different, but sometimes a central party has incentives to lie over, for example, the origin of a specific product in order to make it more appealing. The difference is, in simple terms, in the incentives.

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