Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#3798

  1. Why is it important that the blocks are cryptographically linked together?
    A: It makes the blockchain more secure as having all the blocks cryptographically linked make the chain immutable, preventing any miner changing any of the blocks in the existing chain.

  2. What does the block structure look like in bitcoin?
    A: Each block includes the block size information, block header containing the nonce and the previous block hash, transaction count and the transaction data.

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#3799

  1. It’s important that the blocks are cryptographically linked to ensure security and immutability.
    Previous transactions cannot be altered because it will break the cryptographically linked blockchain

  2. Current block hash
    Input
    Output
    Nonce

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#3800
  1. Why is it important that the blocks are cryptographically linked together?
    Without link blocks will not be added to block-chain. They contain important information for previous blocks (Source + Destination blocks)
  2. What does the block structure look like in bitcoin?
    Block contains transactions, hash function of previous block and linked list
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#3801

  1. It is important that blocks are cryptographically linked together because it makes it extremely difficult to change previous transactions. When a previous transaction is changed, the hashes for all the other blocks are changed causing them all to be mined again.

  2. A block in bitcoin is made out of transactions with inputs (UTXOs) and outputs, and a hash.

1 Like
#3802

  1. Why is it important that the blocks are cryptographically linked together?
    Because cryptography renders the linked blocks fundamentally immutable.

  2. What does the block structure look like in bitcoin?
    A previous or initial hash, internal data content, a nonce, and a newly generated hash accumulated from this data.

1 Like
#3803

1.Why is it important that the blocks are cryptographically linked together?
This helps prevent the data from being altered. Data immutability.
2.What does the block structure look like in bitcoin?
Prev hash+tx list+nonce

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#3804

  1. Cryptographically linked blocks ensures immutability of the blockchains.

  2. The block structure includes hash of previous block with timestamp, transaction data and nonce.

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#3805

1.Because that makes it almost impossible to change content of blockchain. That ensure integrity of blockchain.
2.Miners make a new block by hashing hash of previous block, TXs list and nonce. Once a miner can get a low enough target, the new block will be linked and appended to a block. So all connected blocks uses previous block data.

2 Likes
#3806
  1. It increases the security of the blockchain (through the concept of immutability). Any change in the block would alert the other nodes in the blockchain that there are changes being made, which they woudl reject and such the network cannot be tempered with.
  2. It includes the nonce, the previous block hash, transaction data in the block, block number and the hash of the current block.
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#3807

  1. So data can’t be altered

  2. Block#, Nonce, Data, Previous Hash and Hash

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#3808

  1. So data can’t be altered

  2. Block#, Nonce, Data, Previous hash and hash

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#3809
  1. They are linked together for security and so that blocks cannot be altered, ie, if you could change a block all subsequent links would be broken and would have to be re-calculated, it would be impossible to catch up whilst new blocks are being created too.
  2. Block No. * Nonce* Data* Previous block hash * current block hash * Mine
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#3810

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

It is important to secure the integrity of the network and to give the blockchain a good level of transparency.

What does the block structure look like in bitcoin?

The block is composed by:

  • Previous Hash
  • Transactions
  • Nonce

These components are hashed and the next block will take it to hash it.

1 Like
#3811
  1. Why is it important that the blocks are cryptographically linked together?

To increase the security of the blockchain, so that it is virtually impossible to change previous blocks.

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

Each block has a digital footprint called a hash, each hash is composed of the transactions/data, the hash from the previous block and the nonce.

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#3812

1- This way it is pratically impossible to corrupt.

2- A chain :slight_smile:

#3813

1.To make sure the blocks aren’t tampered with.
2.Block-Nonce-Data-Previous Hash-Current Hash.

1 Like
#3814

How do the links in the chain look like? :wink:

#3815
  1. Why is it important that the blocks are cryptographically linked together?
    So there is chain of computed hashes based on block by block hashes so if any of previous blocks is changed it will change all hashes after that one. This ensure data integrity.
  2. What does the block structure look like in bitcoin?
    Block is build from transactions,
    nonce (random number)
    previous block hash
    Based on above new hash is computed from each guessed nonce to be less then the target hash number.
1 Like
#3816

  1. Why is it important that the blocks are cryptographically linked together?
    It is important that the blocks are cryptographically linked together because this adds Security. If anything is changed or removed in a previous block, it will then invalidate every block that follows and every block would then have to be re-mined which would take years.

  2. What does the block structure look like in bitcoin?
    A block on the Bitcoin blockchain has a hash is based on the previous hash plus transaction data plus nonce.

1 Like
#3817

Yeahhh :wink: it’s a hash, a footprint from the transactions data, the hash of the previous block and the nonce. Thanks for the push ! :+1: