Homework on Consensus - Questions

Blockchain and Bitcoin 101
#964

  • What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus is what enables provenance. Since each node has a copy of the ledger only the truth will be accepted to be written into the database because each node has to agree on the truth.

  • How is this different from how truth is determined in a central database?
    Truth comes into question when a database is centralized as the data entry is done by a single entity who can even edit the data after it has been input. In blockchain the truth is verified by multiple nodes before being accepted and written permanently into the ledger.

#965

What does it mean when we say that in blockchain, consensus determine the truth?
The peer network make checks on each other to make sure the information is correct and that each participant is playing by the rule. People wants to make money and so are incentivized to tell the truth in order to be awarded, otherwise their false transaction will be rejected by the peer network.

How is this different from how truth is determined in a central database?
In a central database, the main authority decides what the truth is, instead of having the truth being agreed upon by all the peers. In a blockchain, the truth is distributed among and agreed upon by the peer network.

#966

  1. Multiple decision makers are needed required. Network Validation prevents fraud.
    People have an incentive to find the truth

  2. Database owners can corrupt the data, proof of authority is required, and it is very difficult to audit.

#967

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

    No single party is making a decision but a collective of networks verifying things .

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

    In central database there is only one source to tell you the truth , rather than collective networks verifying things.

#968

  1. The validity of a transaction is validated by nodes on the network running the bitcoin blockchain software. They all have a record in their ledger of the transaction. This is what makes the Bitcoin blockchain slow compared to other blockchain technology. Consensus is the truth…everybody raises their hand and votes in public. Fully transparent.

  2. A central database is like politicians that don’t vote in public. Deals are made behind closed doors. Insiders decide what the truth is.

#969

1:The truth is determined by a network of people insentvised to tellthe truth.
2.With a centralzed network a company or individual determine the truth.

#970

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

    That means that the collective people in the network have to agree on what is or is not true before it can be added to the blockchain.

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

    A centralized database is controlled and can be altered so it’s accuracy has to be trusted versus a consensus which requires less trust to be trusted.

#971

Yes to your last point Sintrality.
In my understanding with blockchain, you dont need trust that the information is correct, the information of legitamit changes to the ledger are made through collective varification from many independant (yet interconnected) nodes or sources by protocol no by persons themselves. And because of immutability, every transation every created on the blockchain is recorded in the ledger and cannot be removed or changed. Its practically impossible to hack, or cheat the ledger.
Where as in a central database, if someone had administrative and technical access, they could change many entrys and modify mulitple outcomes and still balance the ledger.

Thanks for the quesitons, I hope my answer helped

#972

Consensus is known as a verified, confirmed transaction between parties involved. Thus making a trust-less, decentralised model and the consensus is empowered through financial incentive.

#973
  1. Because all the nodes in the database needs to agree to the new transactions that are coming in and therefore removing the trust.
  2. A central database require trust and can be manipulated by people (removing, adding without confirmations)
#974

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus removes trust by verifying the system

  2. How is this different from how truth is determined in a central database?
    In Commerce consensus creates a network of entities that can verify different stages of a supply chain.Consensus is built on Financial Incentives. This allows all participating parties to have a stake at becoming profitable

#975

  1. In order for a transaction to be accepted on the blockchain, at least 51% of the computers storing the ledger must agree to that transaction.

  2. In a central database, the person or entity that controls that database determines what is changed/added to the database.

#976

  1. It means that majority of the participants agree that the given data is accurate and allow it to be added to the blockchain.

  2. In a central database, the truth is determined only by the single entity that has the permission to add/modify/delete the data.

#977

It means that if everybody agree it s the truth its the truth

#978
  1. Consensus determines truth because multiple entities are required to agree on the truth or otherwise of a transaction .
  2. With a central database there is generally only one entity that determines the “truth”.
#979
  1. It means that the truth is always the one agreed by the majority of the network. False transactions are instantly kicked out beacuse they are not reached via consensus aka. the mutual agreement of the network
  2. In central databases you have to trust the central party and theres no way of proving if he’s telling the truth.
#980

In blockchain when we say consensus determine the truth it means network of computers verify the transactions and then only send to the blockchain network only if everyone agrees to the transaction.

In central database things are not transparent as we do not know the source. For example: if a pickle company claims the ingredient list in a jar is accurate but that is not actually made 100% by them then there is a chance story can be different. If it is decentralised then there is a transparency as network computers involve in consensus are incentivised for confirming the transactions and if they are not truthful then they will be penalised.

#981

  1. It means that a system of interconnected computers on a decentralised network agree to which transactions or information is valid / invalid on the public ledger. They do this by removing trust mechanisms and motivating agreement (consensus) by means of financial incentives.

  2. In a central database, information can be changed or manipulated by whomever controls the database. Acceptance of the information contained in a centralised database is therefore dependent on the trustworthiness of the database owner.

#982
  1. In the blockchain a record is being marked only if there is agreement among a certain portion of the computers in the network. Otherwise the transaction is not recorded in the ledger.
  2. In a centralized system the main power character defines what is true and what is false.
#983

  1. It means that in order for some information to be added to the ledger, everyone (miners) need to agree on this information. + miners are incentivised to validate the truth (whereas they loose money if not). Wrong information is not added to the blockchain/ ledger. This process is called consensus.

  2. In a centralised database, there is often one authority than can decide what is true or not, and can modify the database. In bitcoin, the database cannot be changed + it is not centralised / there is not central authority.