Homework on Consensus - Questions

Blockchain and Bitcoin 101
#884

Homework on Consensus - Questions

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus determines the truth by, I am guessing here, that some majority of nodes have agreed on the truth or validity of transactions. Again, all this blockchain knowledge is still relatively new to me but I am personally internally struggling to agree that the blockchain truth is the real truth even if enough nodes agree or reach consensus.

  2. How is this different from how truth is determined in a central database?
    The “trueness” of data in a centralized database is only relative to trueness of the data input from a single source.

1 Like
#885

Consensus verifies from many different sources to confirm that one piece of information is correct unlike central databases where information is not checked.

1 Like
#886
  1. distributed nodes are financially incentivized to be honest. When the majority of nodes determine a block to be valid, it is considered to be a fact and the block is committed to the blockchain. There is no trust involved.
  2. In a traditional database transactions are authorized by rights granted by an administrator, a third party. The administrator has to be trusted.
1 Like
#887
  1. A public ledger that all validators can see who owns what, how much they have and if they have the authority to do a transaction ( private keys )
    2.central databases will not be able to determine if a bad actor input wrong data
1 Like
#888

Answer:
1- The network of nodes challenge requests for data entry to the Blockchain. They do this by verifying the facts (yes the address has the tokens it wants to transfer) or (yes these eggs are free range, because we can see that you took delivery from the free range farm, who’s is supplied by the eco friendly grain farmer etc.) Once the nodes can verify, a consensus across the network is reached and the data is added to the Blockchain.

2- A central database can be updated with false information be it intentional or not and there may only be one current copy of the database. The data added to a central database will not have hundreds or thousands of insentivised nodes (with an exact copy of the verified database) looking for any discrepancies before data in permanently added

1 Like
#889

Each node’s calculations agreeing with each other determines truth in blockchain, incentivized by reimbursement. Central database truth is determined by external audit

1 Like
#890

  1. The full blockchain network is in agreement that the truth is so. Nothing can be added if all players do not agree.

  2. The truth can easily be altered in a central database, without any kind of verification from any other party.

1 Like
#891
  1. Consensus is a collective agreement on the truth, which involves verification.
  2. Truth is determined through trust and relying on a single point of verification, as opposed to cross examination, or consensus.
1 Like
#892

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    A network of computers looks at every transaction to see if it meets the criteria to be recorded. One computer alone does not decide that. The process is decentralized, therefore the validity of transactions is less prone to tampering.

  2. How is this different from how truth is determined in a central database?
    A central database can be targeted and tampered with to provide inaccurate transaction records. Decentralization makes this less likely to happen by having a network clear the transaction instead of one node. The effort required to compromise a network is an order of magnitude higher than for one node.

1 Like
#893
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    There has to be agreement otherwise it is not truth
  2. How is this different from how truth is determined in a central database?
    There are incentives to tell the truth, and be in agreement, with a database there are incentives to not be truthfull
1 Like
#894
  1. What does it mean when we say that in blockchain, consensus determine the truth?

Answer - A transaction is not committed to the blockchain until the transaction is agreed upon and verified within the consensus.
2. How is this different from how truth is determined in a central database?

Answer - In a central database transaction are committed based on permissions provided by central or local authority. Any one individual can update the database with the correct permission without consensus.

1 Like
#895
  1. Everybody verifies something, then agrees on what was verified.
  2. In a centralized database, you have to trust the owner based on their reputation (or an audit firm) and take its/their word for the quality of the information.
1 Like
#896
  1. Consensus doesn’t removes a need in trust and as a result gives a 100% truth.
  2. Central database can be controlled and as a result it requires trust.
1 Like
#897
  1. Through incentivizing the network participants, the network has to agree for something to be added to the ledger. If it’s deemed false, it get discarded and the bad actor may lose its credibility.
  2. In a central database, “truth” is whatever the database says it is. This can be changed or the data could have been incorrect when it was sent to the db. No one can argue it’s truthness
1 Like
#898
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    In blockchain the process is decentralized, so to validate an information or transaction there needs to be an agreement with all nodes in a network, before it can added into the blockchain. This enables the transaction on a blockchain to be considered “the truth”
  2. How is this different from how truth is determined in a central database?
    In a central database there is no financial incentive to be transparent in a central datable.
1 Like
#899

[1] In the context of a blockchain, consensus determines truth means that at least the majority of the nodes in the blockchain agree with a transaction.

[2] How the above differs from a central database is that with the blockchain and its nodes, the decision of what is truth is purely algorithmic and open to the public. With the central database, books can be easily cooked by those who have access; plus majority of the time these systems are closed ones.

1 Like
#900

  1. Consensus in blockchain determines the truth by the network of users all agreeing on what the “truth” is. One or two individuals do not have the final say.

  2. A central database is not being held accountable by the entire network of users on the blockchain. A central database would have all the power to alter the “truth” at will, unlike a decentralized database that requires and incentivizes everyone to agree and “tell the truth.”

1 Like
#901
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    It means that everyone in the blockchain has talked to each other and is in agreement. Without agreement there will be never consensus. Further, to achieve agreement many different people have spoken to each other and the more people speak to each other the nearer one gets to a consensus. Consensus will only be achieved until full agreement is achieved among all participating parties in the block chain.
  2. How is this different from how truth is determined in a central database?
    In database the truth could be achieved only by one person, this because the person has not communicated with anybody else. So this is only one persons opinion really. So it is not a consensus at all as it is only one persons opinion.
1 Like
#902

  1. It means that all the actors involved in the maintenance of the network must agree on a change to the blockchain, in a decentralised manner. No one individual can proclaim a truth, all must agree.

  2. In a centralised database, the main entity or administrator can decide if an information is true or not. It opens the door to corruption or human error. In the case of blockchain, the verification of all the nodes allow a trustless consensus. It basically works as a mathematically-based peer-review.

1 Like
#903
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus removes trust and its achieved through financial incentives. People actually gain/earn money by being honest. If you’re dishonest you lose money.
  2. How is this different from how truth is determined in a central database?
    Central database has the authority or its the decision maker to determine whether a copy of transaction is legitimate or not. Whereas a single copy of transaction in a node held by public ledger can’t determine on its own whether a copy of transaction is held true or not.
1 Like