Homework on Consensus - Questions

[Christine_Roy]

2. In a central database the verifiability of information is only based on trust, is not verified through independent consensus, nor is there any consequence to making false statements. Any information can be modified by the central authority at will.

[Dvid]

1. Consensus determines the truth in blockchain via a built-in accountability mechanism, where multiple actors verify if a transaction or figure is correct. When a transaction or ledger balance is verified by the multiple verifications, it has achieved consensus.

2. A central database determines truth by verifying a transaction or ledger balance against a standard of truth determined by one principal. There is no inherent incentive to be transparent, and no built-in accountability within the system.

[Leonard_Gohlke]

1. Consensus is removing trust, because every transaction made has to be verified by the “Supply Network”.

2. If one part of a central database is corrupted, then truth is altered.

[rkoel]

1. all the computers/nodes in the blockchain check the data and are incentivized to tell the truth about the data. this leads to concensus among the computers.
2. it is decentral and therefore trustless. in a central database you have to trust one group or person that the data is correct

[MAK10]

1. Consensus determines the truth as all nodes in the network must agree that a transaction has occurred or is valid(for example does the person have enough resources in their wallet)
2. Only one party is deciding on something and not a group of nodes so the party can be dishonest and nothing will be double checked. In the blockchain we are intensified to tell the truth as you will make more money and it you are dishonest you will lose money

[jae_mclean]

In blockchain consensus determines the truth by utilising a global comunity of computers (nodes) who verify incoming data as a community when data is mathematically proven by all nodes to be true they are then added to the blockchain ledger.

A central database can be altered at source by those who control the database. creating a system of trust. the blockchain is decentralised and is based on truth.

[JoseE]

1. Consensus gives us the possibility to verify that whatever is being said to have been done, was actually done, either a transaction or a process
2. A central database can be corrupted, changed or simply mistaken, consensus let us verify with various nodes that have a copy of the database that indeed, the action was made

[Hels]

1. Decentralised nodes on the blockchain verify transactions and all of the nodes need to agree that the transaction can go ahead. Decentralisation means that there isn’t any personal interest in being anything other than truthful because the blockchain is designed to reward truthfulness.
2. In a central database - truth is verified by the individual people who create the database and so we have to trust those people even though we can’t really know whether they’re being honest.

[NickCryptoInvestor]

1. What does it mean when we say that in blockchain, consensus determine the truth?
   It means that any transaction will be verfied by the network of the blockchain nodes, if a majority of them validate it then a consensus if found and is true

2. How is this different from how truth is determined in a central database?
   A central database can corrupt the transaction and no verification ill be done by any other parties, so this will never be as secure as blockchains are

[pacheco66]

@ivan

1. What does it mean when we say that in blockchain, consensus determine the truth?
2. How is this different from how truth is determined in a central database?

1. What does it mean when we say that in blockchain, consensus determine the truth?
   Each computer (node) running the bitcoin blockchain will verify when a new transation is created. These nodes are financially incentivized(miners) to verify these transaction as true when more than 50% of the nodes come to a “consensus”
2. How is this different from how truth is determined in a central database?
   The truth is determined by the centralized power.

[Shilan_D]

1. It means that a number of nodes instead of one agent confirm that something is true
2. The difference is that the truth is recorded on a public ledger that all the nodes have access to.

[Lara1mariah]

• What does it mean when we say that in blockchain, consensus determine the truth?
  The network of computers all look at the blockchain and determine whether something did or did not in fact happen, since there are many computers in the network they all come to a consensus on the truth. The network is financially incentivized to be honest and even if one computer tries to lie, the others will outnumber the liar.

• How is this different from how truth is determined in a central database?
  In a central database there is no way for outsiders to determine whether something is true or not. The central database might be financially incentivized to lie in order to increase profits and consumers have to trust a company to be honest.

[Diegofraga]

It’s mean, they have to agreed it’s good and can be add to the ledger!

It’s different because they can edit the database!

[Martini]

1. It means all participants verify transactions, and if consensus is found all participant agree, that a transaction is true. 

2. Truth in a central database is based on trust. The trust is build on a) reputation, b) certification, c) authority.

[Claudio]

1. What does it mean when we say that in blockchain, consensus determines the truth?
   If the majority of participants of a blockchain (nodes) verify and validate a transaction a consensus is found about a new state is found and recorded as true in the ledger. The participants of the network/market/blockchain do not have to trust a central entity (trustless system).

2. How is this different from how truth is determined in a central database?
   In a central db, a central agent is defining the ‘truth’, all that work/deal with that central agent have to trust the central entity (not a trustless system).

[Bridge61]

the network checkes evertything and everyone has to come to the same answer, so by checking the info you dont have to trust in words.

You need a party to have access to the info and you have to rely on them and it will cost a fee.

[Heather16]

1. What does it mean when we say that in blockchain, consensus determines the truth?
   In a blockchain, the members of the network need to agree on the truth in order to add data to the blockchain.
2. How is this different from how truth is determined in a central database?
   On a blockchain, truth is determined in a trustless manner, whereas in a central database there is a need to trust the person or company which is managing the database.

[MOS]

1. All network transactions are verified by nodes.
2. Truth in a central database is reliant on human trust.

[dhill27103]

1. Consensus is achieved by multiple computers that share the blockchain confirm that a transfer of value or a product from one person to another is a legitimate transaction. They confirm that the selling party had the item or value to send, and the receiving party paid for the value. All of the information on the blockchain is shared and verified by these computers, and so consensus is reached after they confirm the transaction.

2. A central database does not have access to the other databases with the supplier of the value and so it does not know if it is a legitimate transaction. It is owned by one party and thus only has access to the information provided thus it cannot reach consensus with other parties.

[tony1999]

1. When there is consensus, it means every acting player in the network (or chain) agrees on a particular thing, making it trustless and verifiable.
2. In a centralized database, there is no consensus, as the truth is determined by only one of the acting players (the authority), and the rest of the players just have to trust the authority.