Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#1447
  1. it makes changing them infeasible.
  2. The block structure on bitcoin looks like a blockchain. a chain of blocks where the blocks contain the previous hash, the data, the nonce, and the current hash.
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#1448

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    – Cryptographically linked blocks provide added security to the network and makes the network
    practically tamper resistant by making it so that if a block is changed then the hash of that block and the hash of all prior and subsequent block will change and have to be re-mined.

  2. What does the block structure look like in bitcoin?
    – Each added block consists of the hash of the following:
    1.) The hash of the previous block
    2.) The current block’s data
    3.) The nonce

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#1449

  1. It ensures immutability and thus security of the blockchain network.

  2. It reads from left to right, and is an ordered series of a back linked list of block transactions. Each block contains the block number, the hash of the previous block, the nonce, and the hash of the current block.

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#1450

  1. In order to change a block it will be necessary to change all the blocks that came after. It makes the blockchain theoretically immutable.

  2. Block hash is formed by previous block hash + transactions + nonce

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#1451
  1. so that changes cannot be made to previous transactions (not allow double spending)
  2. The block includes the following:
    nonce - random number
    data - Transactions
    Previous Hash - previous block
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#1452
  • Why is it important that the blocks are cryptographically linked together?

this is to ensure that it is not easier changed. if one block is changed the link is broken and the chain will be invalid

  • What does the block structure look like in bitcoin?

the block of a bitcoin includes the nonce, transactions and parent hash

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#1453

  1. this ensures that previous blocks cannot be changed, hence data cannot be altered

  2. nounce, transaction, hash of previous block, hash of current block

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#1454

  1. for greater network security. Any changes to a block breaks the link to the entire chain. This protects the integrity of the blockchain.

  2. hash of block is based on previous block, nounce must be lower than the target.

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#1455

Why is it important that the blocks are cryptographically linked together? This ensures the immutability of the blockchain; the slightest change to one of the previous transactions within a block will have a cascading alteration for all subsequent blocks, which will ultimately be rejected by all of the nodes.

What does the block structure look like in bitcoin? It consists of the Nonce, Transactions, and previous Hash to form the current Block’s Hash. The Nonce is randomly guessed until it achieves a block hash that is lower than the target number. The network sets the Hash target based on the number of nodes, the higher the participation on the network, the greater the difficulty by setting the block hash target to be lower.

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#1456

1. Why is it important that the blocks are cryptographically linked together?

To ensure the security and integrity of the blockchain network and to ensure there are no double spends. It prevents transactions in previous blocks from being changed (if transactions in previous blocks were changed it would break the links to all the following blocks). It ensures that all miners follow the rules of the blockchain.

2. What does the block structure look like in bitcoin?

Hash from the previous block
List of transactions (UTXOs)
Nonce
Timestamp
Difficulty target
Block size

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#1457

Nonce is just a number used by miners to find the resulting hash that is below a target :slight_smile:

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#1458
  1. Why is it important that the blocks are cryptographically linked together?
    So you can not change the previous block without changing the following. In this way you can not alter previous transactions.
  2. What does the block structure look like in bitcoin?
    It cointains hash from previous block, transactions and nonce.
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#1459

1 - It makes all most impossible to change the data and break the rules, because will you have to change all blocks that are linked. Almost impossible

2 - Hash of previous and Hash of the current block. Also the nounce, and transcation list

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#1460

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    So that any changes will produce a new hash which will invalidate the hash in the next block
  2. What does the block structure look like in bitcoin?
    A block represents the present and contains its past and future.Each time it is completed it becomes part of the past as it has a permanent record of past transactions and gives way to a new block where new transactions are recorded.A ledger that makes previous recorded transactions tamper proof
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#1461

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?

Answer:
By having every block cryptographically linked makes every block unique but also links them together due to its way each block is created.
Witch results in that the blocks within the blockchain are difficult to manipulate and make them secure.

  1. What does the block structure look like in bitcoin?

Answer:
The block structure is based on previews Hash
Transaction list on the current block and the random number named Nonce.

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#1462

1.- In order to avoid tampering of the ledger.

2.- Multiple blocks sharing the same information and cryptographically linked together.

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#1463
  • Why is it important that the blocks are cryptographically linked together?
    So when something is changed on a block it effects all of them. Also for security and no double spending
  • What does the block structure look like in bitcoin?
    Hash
    Previous hash
    Transaction list
    Nonce
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#1464

1.) It is important to have all the blocks cryptographically linked together for security of the network so that it would be near impossible to successfully hack or change anything in a previous block without the network rejecting the changed block and continuing forward with the longest blockchain with verified POW.

2.) The block structure includes; the previous block’s hash, transaction list & the Nonce that the miner guessed correctly, (which has to be between 0 and the Target number to be accepted.)

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#1465

  1. It is important because the blocks are linked together by information from previous blocks. Therefore, if the integrity of the data changes then the links are broken. To help maintain data integrity, miners are rewarded in tx fees and block rewards for following the rules and helping secure the blockchain.

  2. The block structure consist of hash from previous block, transaction list and nonce

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#1466

  1. To keep the track of all previous transaction, so that any node in the block chain can verify the validity of new transaction before accepting it in its mempool. Also when blocks are cryptographically linked together, it will prevent any dishonest miner to change any data in previously mined blocks.

  2. In bitcoin a block consists of hash of the previous block, list of transactions in that block , a nonce and hash of the block itself which is derived from all these three.

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