Homework on Consensus - Questions

Blockchain and Bitcoin 101
#3255

What does it mean when we say that in blockchain, consensus determines the truth?
Only “true” transactions/events make it into the blockchain because prior to adding any transaction/event, each node on the blockchain must agree that the transaction/event is a legitimate one. The honesty of each blockchain node is ensured because each is financially incentivised to tell the truth.

How is this different from how truth is determined in a central database?
In a centralised DB, there is a single decision maker or decision-making company or authority so the truth can be changed to suit that decision maker’s motives, and mistakes can be made by this decision maker thereby potentially creating a false truth.

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#3256

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Each transaction is validated by all the computers on the network.
    Each computer performs an independent, unbiased check of the results.
    The resulting ‘consensus’ or agreement becomes ‘truth’ or valid - is accepted and stored on the blockchain.

  2. How is this different from how truth is determined in a central database?
    You have to trust the authority is sharing data that is complete and unedited.
    Also a central database is more vulnerable to security breaches being in a single physical location and being controlled by a few people with the right level of access.

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#3257

Homework on Consensus - Answers

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Answer: With a blockchain multiple nodes are involved when verifying if a transaction should be added or not. Nodes are incentivised to tell the truth. The nodes have to reach a consensus.

  2. How is this different from how truth is determined in a central database?
    Answer: With a blockchain you remove trust. With a central database you have to trust a centralised entity to tell the truth.

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#3258

  1. Consensus determines the truth in blockchain, because every transaction or piece of data written in the blockchain has to be verified by the different nodes of the network. Only when the nodes reach consensus, the transaction etc. will be confirmed.

  2. In a central database all users which are authorized to create, change or delete data from the database usually act on their own. There is no decentralized mechanism to verify the truth of the data. The readers have to trust that the author writes the truth.

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#3259
  • What does it mean when we say that in blockchain, consensus determine the truth?
  • All participants agree on the transaction in order for it to be part of the blockchain.
  • How is this different from how truth is determined in a central database?
  • A central party is in control of the transaction and can alter transactions without agreement from participants.
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#3260

  1. In blockchain, all networks will verify if all information is in alignment and is correct. When all networks agree that all information is correct, they reach a consensus that indeed the information is correct or is incorrect.

  2. In a central database, one party, or a small party usually determines whether something is correct. This allows for errors or manipulation of the information to show what they want you to believe is the truth.

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#3261
  1. Consensus determines truth by a network of computers confirming certain information to be true based on the collective knowledge the blockchain/network has documented and agreed on. With the entirety of the system incentivized to play by the rules, there is simply no reason to cheat the data even if you tried. That being said, we can trust the verifications on the blockchain rather than the farmer with “ridiculously healthy” cows.
  2. Because these decentralized databases determine truth collectively with the help of several parties. It is a group decision that has no ego to lose like a company claiming one thing to be true, because they may not be playing by the rules. The blockchain is simply: “what is true and what is not” based upon past agreements.
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#3262
  1. What does it mean when we say that in blockchain, consensus determine the truth?
  • In blockchain the truth is determined collectively by all its members -> this eliminates trust (following the rule of thumb like “don’t trust… verify”) and is achieved through incentives.
  1. How is this different from how truth is determined in a central database?
  • Unlike blockchain (distributed ledger technology), in the case of central database, the truth can be decided by one, central entity (and we either trust them or not).
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#3263

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

The blockchain network of computers need to agree, and only on networks agreement that it is good will it be added to the ledger.

Consensus - removes trust, achieves incentive and provides the truth by verified network of nodes that “all” play by the rules.

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

The central database generates a trust environment that can be added to, subtracted from, hacked and crashed; and the decentralized consensus based blockchain eliminates authority, maximizes tracing, ensures security, as it provides incentive for the truth.

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#3264

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

The blockchain network of computers need to agree, and only on networks agreement that it is good will it be added to the ledger.

Consensus - removes trust, achieves incentive and provides the truth by verified network of nodes that “all” play by the rules.

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

The central database generates a trust environment that can be added to, subtracted from, hacked and crashed; and the decentralized consensus based blockchain eliminates authority, maximizes tracing, ensures security, as it provides incentive for the truth.

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#3265
  1. Blockchain consensus is removing trust by incentive which lets you gain by being honest.
  2. Normal database is not open to verify by the user, it needs to be audited and therefore it can’t be trusted.
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#3266

Love your work, really very visual! Thanks for sharing

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#3267

  1. Consensus determine the truth because many computer got a copy of the blockchain and they can consult all the datas which make unfalsifiable.

  2. The difference is you to get an fully completed data that is verified by many computers and make it quite impossible to get a wrong data or compromised that’s the huge difference with the original company that could have say what’s to let appear and what to hide.

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#3268

Consensus - Questions
1. What does it mean when we say that in blockchain, consensus determine the truth?
a. In the blockchain we don’t trust, we verify everything. This a true trustless state.

2. How is this different from how truth is determined in a central database?
	a. Here verification cannot be caried out unless you have access. 
       We need to trust the Database Admin and the owner of the central system
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#3269

  1. Truth is determined when a whole network agrees on it. Additionally, this network benefits with financial incentives when playing by the rules.

  2. In centralized databases truth is determined as it fits the controlling entity.

1 Like
#3270
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    All decentralized nodes must agree on a transaction. If one node says send transaction to address x and the other nodes say to address y, the other nodes will be incentivized to say NO and block the “false” transaction.
  2. How is this different from how truth is determined in a central database?
    In a central database, the values inside is the “truth”. That value can be changed by individuals or organizations that has the access to it without consensus and therefore a central database requires high level of trust.
1 Like
#3271
  1. What does it mean when we say that in blockchain, consensus determine the truth?
  • The majority of nodes will determine whether a transaction is a valid one or not. If majority agrees it is valid, it will be added to the ledger, if not: it will be dismissed and will be kept out
  1. How is this different from how truth is determined in a central database?
  • Difference: Central DB entries/records can be manipulated or hacked. Some authority ‘owns’ the DB, so you would have to trust this authority. This is not the case for a blockchain, no trust needed here regarding validity of data (it is trustless)
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#3272

1- What does it mean when we say that in blockchain, consensus determine the truth?
Consensus requires the blockchain to agree to a transaction as this is a decentralized system this prevents intentional or accidental fraud
2- How is this different from how truth is determined in a central database?
A central database can only check against its own record therefore if I instruct the database that I have £1m the database accepts this and I can then perform transactions against this, in blockchain the initial declaration would be rejected as there is no evidence within the blockchain that I have that money

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#3273

  1. Consensus is when everyone is incentivize to tell the truth.

  2. In a central database there is no consensus as it usually relies on a group of people or individual to make that decision.

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#3274

Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    the individual nodes need to agree on a transaction this eliminates the need for trust, the truth is verified in the blockchain
  2. How is this different from how truth is determined in a central database?
    the central database can spin the truth, we have to trust that they don’t do that
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