Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4482

  1. Helps to maintain the integrity of the system.

  2. A bunch of blocks of transactions linked together by using the hash of the previous block.

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#4483
  1. It is important that blocks are cryptographically linked together to ensure no previous transactions/blocks can be changed which secures the network.
  2. Block structure in Bitcoin consists of: Previous block hash, Transaction data, and nonce.
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#4484

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
  • to prevent changes to any previous blocks and their transaction lists.
  1. What does the block structure look like in bitcoin?
  • hash looks like: previous hash + transaction list + nonce.
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#4485
  1. Helps with preventing data alteration. Data immutability
  2. Transaction hash (TX), inputs and outputs.
#4486

And previous block hash.

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#4487

Thanks Maki for the additional answer!!!

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#4488
  1. Why is it important that the blocks are cryptographically linked together? to be able to setup a blockchain of integrity to secure the network to ensure no double spending no reverse transactions
  2. What does the block structure look like in bitcoin? the hashes of the block is based on the transactions in the block plus the previous hash and the nonce that most likely needs to be guessed
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#4489

  1. It is important that the blocks are cryptographically linked together because it makes it harder to change the data of existing blocks. So that if one block is changed, all following blocks must be re-mined as well.

  2. A block is made up of transactions, nonce, hash of the parent block

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#4490

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

So not anyone can go back and change the data to try and create there own block.

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

Header
Hash of previous Block, Time Stamp, Nonce
Body
Tx Data

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#4491

  1. Why is it important that the blocks are cryptographically linked together?
    It is important because if someone try to change something in one single block, every other block would need to change too. If you change an information in a block, the link between this block and the next would be broken. So this makes it practically impossible to input false information into the blocks.

  2. What does the block structure look like in bitcoin?
    Each block’s hash is based on the list of transactions inside it, a nonce and the previous block’s hash. So every block is linked to the previous and the next blocks. Any corrupted information inside a block would break these links.

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#4492

  1. So that any changes to the previous blocks would alter the hash of the following blocks, invalidating the following chain and results in a more secure network.

  2. It looks like a chain of hashed fingerprints of data, on which each blocks hash is based on the previous blocks hash.

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#4493

1. Why is it important that the blocks are cryptographically linked together?
For security , to prevent data from being altered , maintains integerity , and more difficult for bad actors to obstruct the blockchain .

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

They include all transactions going back to the genesis block (1st block) with a unique hash that is tied to the prior block. They have headers , transactions , hash of the prior block and NONCE which need to be solved in order to spend the next block

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#4494

  1. Why is it important that the blocks are cryptographically linked together?
    the link is important to secure the chain and keep the integrity of the data; if someone or a system tried to change the data the whole link would change; thus the network won’t accept the data. Thus btc blockchain makes it immutable.

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

block.structure { 
 past.block.hash;
 nonce (random generated number);
& transaction data; 
}
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#4495
  1. This is important to ensure that no previous block’s data can be changed without breaking the rest of the blocks.
  2. Blocks have a hash that is calculated based on the previous block’s hash, the data within the block, and the nonce.
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#4496
  1. Why is it important that the blocks are cryptographically linked together?

It is important because if there are changes in the data it will break the links and blocks of the future transactions.

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

The new hash is created from the previous hash, transaction and nonce.

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#4497

  1. Why is it important that the blocks are cryptographically linked together?
    Blocks are cryptographically linked together for the security and provenance of the blockchain.

  2. What does the block structure look like in bitcoin?
    In bitcoin a block will contain the previous block’s hash number, transaction data, and the nonce. By combining all 3 we create the new hash for the new block.

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#4498
  1. Why is it important that the blocks are cryptographically linked together?

It is important that the blocks are cryptographically linked together since the hash of the current block is based on and contains the hash of the previous block + data + nonce. This guarantees the integrity of the transactions as any change to the transactions in a block will invalidate the hash in the next block and in subsequent blocks. This makes tampering with the transactions in any of the blocks in a blockchain a costly and immensely difficult task. It is a deterrent that prevents any change in any of the blocks and keeps their contents intact.

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

The block structure consists of block identifiers, block header and transactions.

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#4499
  1. Why is it important that the blocks are cryptographically linked together?
    -> to prevent any tx changes in confirmed blocks. any changes would affect all of the blocks after the changed block.
  2. What does the block structure look like in bitcoin?
    -> previous hash, tx list, block reward and nonce.
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#4500

  1. It makes them secure and consensus. Without being linked it is not possible to lookup transaction history. It would not be possible to make transaction because there would not me UTXO’s.

  2. nonce; transaction list, previous hash, hash, block number

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#4501
  1. to ensure the chain continues and secure
    2.hash of previous block, current block transactions and nonce
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