Homework on Consensus - Questions

Blockchain and Bitcoin 101
#3415
  1. Every Participating entity involved agrees to the transaction before being recorded and approved.
  2. Central database has control of its data, and can obscure it without outside prevention.
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#3416

  1. Consensus is a verification mechanism in which nodes (verifiers) in a blockchain agree on the validity of a transaction. If someone is trying to cheat the system (eg send more bitcoin than they have in their wallet) the consensus mechanism will not agree to proceed and the transaction is ignored.

  2. A central database requires trust from a centralised entity in which it is stored. Since data is stored in a single source, it is prone to tampering, hacking, and amendments, without any transparency.

1 Like
#3417
  1. In blockchain consensus is reached by a network of computers that verify the truth & agree it is the truth.
  2. In a central database, you must rely on the party that controls the database & what they say is the truth.
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#3418

1 consensus is the agreement of the network
2 individuals chose what is the truth.

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#3419

  1. On the BlockChain, when all nodes accept a transaction it is accepted and written onto a Block. The consensus is reached before it is written. Truth is the transactions in a Block.

  2. The owner of DB can change or erase the DB which the public cannot view or verify. This is the opposite of transactions in BlockChain.

1 Like
#3420
  1. When a decision is made, several parties (nodes) come to a decision of what is true and what is false.
  2. In a central database, one person, or a group of people determine the truth. However, in a decentralised network, more than one person, or group of people verify what is true and what is not. This removes trust through incentives and we can see what is legitimate and what is not.
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#3421

1. What does it mean when we say that in blockchain, consensus determines the truth?
In blockchain, “consensus determines the truth” means that multiple nodes are monetarily incentivized to confirm transactions. Validators are penalized for faking transactions. Therefore, the network is unified via the drive to make a profit. Moreover, having the ledger decentralized means there is a natural disaster recovery SLA of 0. As in, the network can keep running in the even of one or a few nodes going offline. This is because the same copy of the ledger is spread amongst many nodes. Consensus removes trust and centralization which leads to verification and transparency.

2. How is this different from how truth is determined in a central database?
Central databases rely on trust rather than consensus. These databases can be tampered with, fraudulent data can enter the database by bad actors, and it is extremely difficult and inefficient to audit. The lack of transparency makes it difficult to verify. Central databases also have high DR SLAs because it is up to a central authority to backup and restore the data in multiple regions which pales in comparison to having many node operators as backups.

2 Likes
#3422

What does it mean when we say that in blockchain, consensus determine the truth?
It means that we take whatever multiple parties agree on being true for the actual and only truth.

How is this different from how truth is determined in a central database?
In a central database the “truth” depends on trust towards the owner/maintainer of the centralised database. In consensus there is no need for trust, therefore trust is no factor. (Trustless)

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#3423

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    Consensus determine the truth because it verifies all transactions in the ledger to eventually reach a decision by agreement; therefore, if the information is true then it proceed or if it’s false then it rejected.

  2. How is this different from how truth is determined in a central database?
    It is different because in a central database the truth is determined by trust.

2 Likes
#3424

  1. The saying that consensus determines the truth in blockchain means that network of computers on the public ledger verifies a transaction. If one or more computers cannot verify a transaction claiming to be made, that transaction is ignored and is not posted on the block.

  2. This is different from how truth is determined in a central database because in that database there is not a decentralized group with access to a public record of information verifying if a transaction was made. A central database is trust based, whereas the public ledger of the blockchain is trustless.

1 Like
#3425

Homework on Consensus - Questions

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

This means that everyone has to verify the information is correct.
2. How is this different from how truth is determined in a central database?

It is incentivized for being truthful when things are verified.

1 Like
#3426
  1. Consensus means that decisions are taken together, and information is only confirmed if all parties involved can confirm it. So if everybody says, that something happened, it can be seen as truth. This works as people are incentivized to be honest.
  2. In a central database the decisions are made by a few people/entities and are not based on consensus. Additionally, as in a database information can be deleted and changed, it’s prone to manipulation in the first place.
2 Likes
#3427

All that can be done is to trust strangers and hope they don’t cheat; that they play by the rules

1 Like
#3428

  1. What does it mean when we say that in blockchain, consensus determine the truth?
    In blockchain, consensus determines the truth via incentivizing everyone the tell the truth. The consensus is received via the blockchains provenance. Where one company cannot claim to produce “organic product xxx” when a key ingredient they receive from another company is not to the required standard.

  2. How is this different from how truth is determined in a central database?
    Truth in a central database can only be determined by one central database, this can lead to adding and subtracting or fudging stats where it cannot be automatically verified via a blockchain.

1 Like
#3429

Homework on Consensus - Questions

1. What does it mean when we say that in blockchain, consensus determines the truth?
-Answer: Consensus is the process of verifying newly received information (the accretion of which is the entire blockchain ledger) via cross-checking. Multiple nodes validate each piece of new information against the existing blockchain and cross-check with other validators. This is the basis on which truth or correctness is determined in a blockchain system.
2. How is this different from how truth is determined in a central database?
-Answer: In a central database a single processor determines the validity of each piece of information received and stored in the database. This means that if there is a fault in that processor the validation process and thus the stored information may also be faulty.

1 Like
#3430

  1. All nodes on the blockchain must agree that the entry is valid before it can be added. It’s the basis for trustlessness. All parties have full visibility into the validity of the data

  2. Blockchain allows for tracing and provenance

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#3431
  1. What does it mean when we say that in blockchain, consensus determine the truth?
    It means all nodes in the network checks all info to be valid by having all transaction history on an open ledger.
  2. How is this different from how truth is determined in a central database?
    A central database can be changed, in consensus the blockchain can not.
1 Like
#3432

  1. Consensus is the mechanism of verification by multiple nodes on the network incentivized to determine what is a valid or invalid transaction.

  2. In a centralized database one party alone controls & determines what is added or excluded from the record from the record of truth.

1 Like
#3433

Homework on Consensus - Questions

1. What does it mean when we say that in blockchain, consensus determine the truth?
What the majority agrees on, is what is on the public ledger.

2. How is this different from how truth is determined in a central database?
The central database determines the truth in a central database. In decentralization the individual parts
as a collectively verify via the public ledger.

1 Like
#3434

  1. Consensus determines truth on the blockchain when nodes agree to complete a transaction.

  2. On a central database, only one user is needed to change data, and therefore that truth is not consensus.

1 Like