Homework on Consensus - Questions

Blockchain and Bitcoin 101
#1971

  1. It means that it was decided by not only one of the party
    but it was all decided by all of them unanimously which what makes the consensus determine the truth. Since in blockchain every participating party is incentivized to play by the rules and by telling the truth, so its necessary for each of them to tell the truth
    consensually in order for them to get incentivized.

  2. Centralized truth is only truth base from the cenralized entity so it is susceptible
    to an alteration anytime if that entity decided to altered it. In other words
    Centralized truth is only truth by the central authority who manages the system
    while blockchain truth is the truth coming from everybody.
    It is like truth of one(centralized database) against truth of everyone(blockchain).

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#1972
  1. In blockchain the network has to agree all new transactions by consensus before being allowed on the blockchain; this process involves verification and financial incentives to tell the truth, so removes need for trust.
  2. A centralised database is usually controlled by single authority with none of the checks and balances afforded by a distributed network - therefore the data can be manipulated, deleted or changed.
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#1973
  1. If all the computers in the blockchain network come to the same answer, if they reach a consensus then the information provided to them had no problems with it, so unless new information is uncovered that will stand as truth.

2.Truth determined from a central database can be altered to the wishes of the owners of the central database owner eg. a bank, this information is basically useless then as one or a group of people can essentially change the story of what happened

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#1974

What does it mean when we say that in blockchain, consensus determine the truth?
The network majority accepts transactions as valid/true,
hence the network is in consensus about what is true.

How is this different from how truth is determined in a central database?
One single entity is in control of which transactions to accepted as valid.
No network consensus has been reached to validate the transaction.

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#1975
  1. Satoshi Nakamoto realized that when the nodes comprising a decentralized network are incentivized to create positive outcomes, that bad actors can only succeed when there are more network nodes seeking nefarious outcomes than positive outcomes. ie: more bad guys than good guys . I am pretty sure that this is the root logic behind the 51% attack I have read about. Consensus is achieved when the majority of nodes agree with an outcome good or bad. Because it is, so far, true that there are more good guys (nodes) than bad guys (nodes), trustless systems, like Bitcoin, can succeed and produce only positive outcomes. 2. Truth in any normal database is determined by comparison of the value of a record field with a predetermined reference datum value where truth is the answer to the question (test) of whether the data is equal to, less than or greater than the reference value.
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#1976

Hi there!! Yes, and not only that if there are more or less bad guys than good guys, as you also need all the bad guys working together!! If there are 100 nodes, and there are 6 groups of 10 bad guys, the only way to attack the network is if they work together, if not, its useless… So its even harder! And more with bitcoin when there are thousands of nodes

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#1977 
What does it mean when we say that in blockchain, consensus determine the truth?

it means that the rule used to determine the data that is consolidated into the block of the chain is what defines what is the truth (past), about a thing being it for instance what transactions are valid for a customer to define its account total value.

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

Teuth in a central database is determined by the current status of the data, to determine the facts that brought the data to the current state of affairs is totally function of the developer that can change data itself and changing process as well not needing for it to ask permission or to keep sync with other copies of the data by its own discretion.

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#1978

What does it mean when we say that in blockchain, consensus determine the truth? Consensus is achieved on the blockchain through multiple nodes on the network that all validate a posted transaction. They are all incentivized with payment to confirm the validity of a transaction once they’ve all come to the same conclusion whether the transaction is valid or not.

How is this different from how truth is determined in a central database? Apart from some mechanisms in place within a centralized database that ensure that the data entered into the posted transaction align with the rules established in the system, there is no further verification that happens; it is simply recorded onto the ledger. There is really no other party there to verify that the transaction is valid or not.

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#1979

  1. Consensus determines the truth because it requires all nodes to agree on what actually took place.

  2. In a central database, one entity is responsible for inputing data and that data can be manipulated. There are no checks and balances from multiple nodes to verify the information.

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#1980

  1. Consensus is the “truth” mechanism used to achieve agreement on the validity and accuracy of incoming data or status of pending processes. This is achieve through a network of multiple validators.

  2. In a centralised database, a central authority is solely in charge of determining validity and accuracy of incoming data and processes. This opens up the possibility of fraud, corruption and inaccuracies depending on the motivation of the central authority.

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#1981

handy resource there! thanks for sharing :slight_smile:

#1982

1 - it means that the various nodes in the network can check, and verify that a transaction occurred,

2 - In a central database, input comes from one (or few) source(s). everyone else has to accept/trust that entry

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#1983

What does it mean when we say that in blockchain, consensus determine the truth?
On a blockchain, power and trust is distributed (or shared) among the network’s stakeholders (e.g. developers, miners, and consumers), rather than concentrated in a single individual or entity (e.g. banks, governments, and financial institutions).
It’s built on the basis of distributed trust: We are trusting everyone in aggregate.

How is this different from how truth is determined in a central database?
In a central database the ‘truth’ is kept in one place by a central entity, where all the trust lies with it.

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#1984

  1. Consensus determines the truth as multiple nodes on the network need to agree on a transaction. If this transaction cannot be verified then it will not be added to the blockchain. All nodes an incentivised to tell the truth as they are rewarded for doing this.

  2. This is different to truth in a central database as there is a need for trust in whoever controls the database. We need to be able to trust the person in charge of the central database. Blockchain is decentralised and therefore trustless.

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#1985

1.What does it mean when we say that in blockchain, consensus determine the truth?
A decentralized and worldwide distributed network of computers that all have a copy of the blockchain is referred to as a network of nodes. These nodes must come to an agreement or consensus about whether or not a transaction or certain information is true, by checking the blockchain for verification.

2.How is this different from how truth is determined in a central database?
This is different in a centralized database because a centralized database and the information obtainable from it is controlled by a small select group of people or possibly just one person that decides for everyone else in the world what is true or not. Nobody receiving that information has any real way of verifying whether or not that information is true on not. The whole world then has to trust that small centralized group to be fair and honest especially when it comes to finance. This has led to and can lead to high amounts of corruption.

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#1986

  1. In blockchain, consensus means that more than one (or a group of) node(s)/network(s) in the blockchain has to come to an agreement that the proof of work or transaction is true or false.

  2. The difference in a central database is that there only one protocol/central network that determines the truth with no real incentive to do so.

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#1987

1 truth is confirmed by more than 1 party/block
2 there is only one party in a central database which can be changed

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#1988

Thanks; great point!

#1989

  1. Consensus keeps the network in check & everyone collectively agrees. It dots its I’s and crosses its T’s for all new transactions.

  2. In a central database, we have a table of “Hoggish Greedly’s” taking all the ledgers and stealing all the Fiat. Hence central databases can be controlled & manipulated.

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#1990

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    -> it is a mechanism in which multiple independent parties verify that a fact stated publicly is in fact correct

  2. How is this different from how truth is determined in a central database?
    -> a central database can be edited to suit needs of central party, therefore you must trust that they are not a bad actor

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