Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#3738

  1. Why is it important that the blocks are cryptographically linked together?
    This is important to prevent double spending, it allows the network to be incredibly difficult to manipulate.

  2. What does the block structure look like in bitcoin?
    The block contains the block number, transactions, the previous hash, the nonce and all of this is considered to create the new hash of the current block.

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#3739

  1. It is important blocks are cryptographically linked so that if changes are made, the link will be broken and the cost of trying to mine an incorrect block will increase.

  2. The block structure looks like a square that has lines where the following are entered: transactions, block number, nonce, the hash of the previous block, the hash of the current block.

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#3740
  1. So that no transactions can be changed in previous blocks because it would break the link to the next block and all that follow.
  2. Block number > Nonce > Transaction Data > Hash of the Previous Block > Hash of current block
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#3741

1- To be sure it is all conected in the ā€œblockchainā€ and make it much more difficult to break it.
2- NONCE+PREVIOUS HASH+TRANSACTIONS

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#3742

  1. Because when they all connected cryptographically, we ensure the integrity of the blocks. We ensure that if even the slightest thing is changed in any of the blocks other blocks wouldnā€™t make sense.

  2. It consists of the previous block hash, block content (usually transaction inputs), and the nonce.

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#3743
  1. Because it prevents people and miners from adding or removing tx from the past blocks. It permits to have an immutable chain
  2. Hash / Version / Time / Bits / Nonce / Hashprev / HashTX / TX
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#3744

  1. If the blocks are not linked together there would just be blocks with transactions that could be altered. Since the blocks have a chain, they are connected and based on each others data, the data is copied from each block and to alter one transaction, the whole blockchain would be invalid since you canā€™t change one bit without it changing the whole hash.

  2. Previous hash, hash of current block, transaction list, Nonce

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#3745

  1. It is important that the blocks are cryptographically linked together to secure the blockchain. So nobody can change a block without noticing.

  2. The block structure starts whit the blockheader contains previous hash from the previous block, the metadata (block version number, difficulty, timstamp), contains the transaction list (Merkel root) and the nonce (proof of work puzzle).

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#3746

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

This is so that it would be nearly impossible for someone to change a block in the blockchain, because to change an existing block, you would have to ā€œre-mineā€ all of the blocks that come after it, including the ones currently being added.

When the blocks are cryptographically linked together, you would have no other way to re-mine the blocks but to guess the nonce and check the hash output - i.e. waste computing power and electricity. So, having the blocks be cryptographically connected secures the blockchain against changes.

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

Each block in the bitcoin blockchain should contain the following:

  • Hash of previous block - secures the blockchain against changes in transaction history
  • Nonce - random number that miners are trying to find
  • Transaction list - contains transactions picked by the miner which will be included in the block if it is successfully added to the blockchain
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#3747
  1. The blocks are cryptographically linked together to protect the integrity of the blockchain. If any one aspect of any block is altered, everything following that change is affected and is no longer validated.
    2.The block structure consists of a series of blocks linked together. Each block is contains the block number, nonce, the data (transaction list) and the hash of the previous block. The result has to be lower than the target (between the target and zero) for the block to be accepted into the blockchain.
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#3748

  1. Why is it important that the blocks are cryptographically linked together?
    To ensure miners donā€™t try to change previous transactions.

  2. What does the block structure look like in bitcoin?
    Blocks comprising of TX, nonces, and hashā€™s that all interlink. If data is changed in one block, it ruins the connection of the whole blockchain.

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#3749

1.each block are connected by hash .miner generate new block 's hash include privous blockā€™s hash ,this makes malicious act to manipulte blockchain almost impossible.
2. like a rope connect with lots of boxes. each box (block) contains txs,previous hash,nonce, and the rope (link) 's generated contain last blockā€™s hash

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#3750
  1. Why is it important that the blocks are cryptographically linked together?

Because this makes it more difficult to go back and change previous data since this will break the chain to the next block and all other next blocks. Ensuring the reliability of the onchain data

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

TX, prev hash and nonce. The hash of the current block is calculated using these variables.

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#3751

1. Why is it important that the blocks are cryptographically linked together?
It ensures the integrity of the blockchain, it causes miners to play by the rules, due to infeasible amount of work required to modify previous blocks.
2. What does the block structure look like in bitcoin?
The block contains the hash from the previous block, the number of the block, the nonce, timestamp, list of transactions and the hash of the block.

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#3752

  1. so there is a contiouse blockchain that gives room for things like the longest pow, making it hard to cheat, leading itself into trustless transactions, a integrity and data immutability

  2. Blockheader (the metadata; what version fo the block is running, the last block, merkleroot, time.current target) Blocksize. the mempool.

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#3753

  1. To prevent a miner from easily changing a transaction.

  2. Previous hash, transaction and nonce.

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#3754

  1. Why is it important that the blocks are cryptographically linked together?
    To prevent someone (a miner) from trying to change something in previous blocks

  2. What does the block structure look like in bitcoin?
    Previous blocks hash + Transactions from the Mempool + Nonce (puzzle the miner solves)

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#3755

  1. Why is it important that the blocks are cryptographically linked together? The links between blocks are important because it ensures the integrity and immutability of the entire chain. That way, if a miner attempts to alter a TX list in any block; the hash of that block and every other block forward in the chain will change and the network will know that something doesnā€™t make sense. As a result, the network will ignore this change.

  2. What does the block structure look like in bitcoin? The structure of a block consists of the hash of the block itself, the TX list of block itself, the hash of the previous block, and the nonce.

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#3756

  1. To ensure security in the system so that no one can alter data in the network

  2. Block structure contains, hash input, nonce, data and transactions

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#3757

1 it is very important because it provides high form of security and insures that blocks remain immutable.
2 transactions, a transaction counter , bock header , the block size and the hash of the previous block.

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