Homework on Consensus - Questions

Blockchain and Bitcoin 101
#803

Consensus
Working together to come to an agreement/conclusion.
etymology: Con (with/together) & Sentire (to feel). One historic use was medical, to describe how the eyes work together

What does it mean when we say that in blockchain, consensus determine the truth?
All parties on the network must agree on new transactions before they are added to the ledger.

How is this different from how truth is determined in a central database?
In a central database, an individual actor can gain access to past records and make arbitrary entries. Aka ‘cooking the books’, ‘lying’, ‘just putting it here because I’m not sure where it really goes’, or ‘making a mistake’.

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#804
  1. With the Consensus, the network detects if a strange transaction has occurred and eliminates it. So if the transaction is present in everyone’s blockchain: it is true, if there is something wrong, it will be removed.
  2. In a central database, the truth is decided by an authority or someone who is not respecting the rules at the time. With a decentralized and trustless system, the truth is “decided” by the whole network.
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#805

  1. Every node on the blockchain must agree that a transaction is true in order to reach consensus. Rather than a central database, a blockain’s transactions are validated by multiple users instead of a centralized source.

  2. In a central database, it is harder to determine the truth because transactions are not required to be validated from other sources.

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#807
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    The network needs to agree on the validity of a transaction before it is written into the ledger.

2 How is this different from how truth is determined in a central database?
A central database requires trust, whereas a blockchain is trustless.

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#808

1.Consensus determines the truth because any information inputted onto the blockchain must be verified by other computers or miners which use historic data to confirm that the information is true. NO single entity can confirm an input on their own.
2. A central database generally does not have a group of overseers to check the validity of the information being inputted.

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#809

What does it mean when we say that in Blockchain, consensus determines the truth?

Since a complete copy of a blockchain resides on a network of systems, multiple systems validate a transaction. So in Blockchain, the truth of a transaction is said to be determined by consensus.

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

One can infer that the truth of a transaction is far more reliably conferred by a consensus among a large number of systems rather than a centralized server that has only one owner and could conceivably be hacked. In a centralized system, if there was suspicion of an error, the current version would have to be compaired with a back-up, offline version. Having multiple copies on multiple online systems makes the validation happen in real-time.

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#810
  1. Consensus removes the trust issues in blockchain and consensus is achieved through incentives.
  2. If a transaction is providing false or misleading information it will simply not be accepted in the blockchain. A centralized database can contrl whatever information enters the database which means that truth is not fully achieved
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#811
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    All or the majority of the involved parties agree on the truth which makes it decentralized and trustless.
  2. How is this different from how truth is determined in a central database?
    One party can decide what is the truth. You have to rely on them to not lie. So you have to trust them.
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#812
  1. What does it mean when we say that in blockchain, consensus determine the truth?

Consensus is the true form of democracy, when the majority (51%) determine what is the truth due to being adequately incentivised to agree on the truth.

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

The “truth” in a central database is determined by who ever controls the database or that one person who has more than the rest, not majority just more.

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#813

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

Consensus is built on Incentives, it is Incentivized to be transparent and precise.
Every server involved need to agree and decide a transaction makes absolute sense. Once verified, the transaction will be accepted into a decentralized immutable database.

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

In central database, the information stored is controlled and overlooked by an authoritative party. Data can easily be monitored, manipulated, and/or erased. The truth is determined by trust.

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#814

1: Consensus allows for a number of computers, without central authority, to verify each entry on the ledger.

2: On a traditional central database, a central authority, individuals employed by that authority or bad actors can add to or remove entries from the database, without oversight.

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#815
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus is built on incentives. Computers on the network are incentivised to tell the truth.
  2. How is this different from how truth is determined in a central database?
    In a central database data can be removed or altered.
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#816
  1. Multiple parties are able to verify whether something is true or false.
  2. Central databases aren’t publicly viewable, you have to take the central authority’s word for it.
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#817

1.Consensus is a dynamic way of reaching agreement in a group. The Blockchain consensus protocol consists of some specific objectives such as coming to an agreement, collaboration, co-operation, equal rights to every node, and mandatory participation of each node in the consensus process. A consensus algorithm aims at finding a common agreement that is a win for the entire network.

2.The database, unlike blockchains, are centralized ledger which is run by an administrator. Databases also exhibit unique feature including the ability to read and write. Here, only the parties with proper access can do Write and Read actions.

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#818
  1. Since there is no central authority, several owners of the nodes has to verify the transaction. Once we have enough number of verifications, the transaction is considered verified, or truth is achieved.
  2. In the central database, we have a central authority that keeps track of all records and defines the truth.
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#819

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    In blockchain network the consensus means that any transaction that is added is verified by all the computers(nodes) in the network. We don’t have trust in a single entity. But in this all the computers verify the data. Also, in the blockchain people are generally rewarded (incentivised) for telling the truth.

  2. How is this different from how truth is determined in a central database?
    In central database even a single person can edit data. It is not verified by everybody. Hence you have to trust that data is true.

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#820
  1. Consensus is when two or more parties are in agreement about something, when consensus is achieved then inevitably this can be defined as truth respectively between parties. (Byzantine general problem)

2.On a central database it is not immutable so there is scope for a party to alter there truth therefore there is no way to know categorically if consensus has been achieved. Block chain is essentially the neutral arbitrator which verifies the truth.

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#821
  1. Consensus determines the truth because multiple parties are required to verify data and they are incentived to keep the truth or they will lose benefits.

2.It is different because multiple parties are required to verify and all information is double checked while a normal blockchain one party can determine the truth. They do not have any incentive to keep truth so they can benefit while lying.

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#822

  1. Blockchain consensus determines the truth because all parties must be in agreement of the information/data.

  2. In a central database anyone can modify information/data it is not verified by involved parties.

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#823

  1. That means that every transaction or actions are verified by the computers of the network and so the consens is made that this transaction is making sense and everyone is playing by the rules. so its true!

  2. in a central data base the truth is determined by a central authority.

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