Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#3938
  1. It is important that blocks are cryptographically linked together because it helps to secure the network. It is virtually impossible to make changes to one block while creating a change in the next block.
  2. The block structure consists of a new hash along with the previous hash and the transaction data and the nonce.
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#3939
  1. Blocks are linked together for security and to ensure that there is no double spend.
  2. The block structure contains the hash, the transaction history, and then the puzzle to be solved, which would include the nonce and a target.
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#3940
  1. Why is it important that the blocks are cryptographically linked together?
    To keep the data of the network safe and unchangeable.
    1. What does the block structure look like in bitcoin?
      block number, nonce number, the tx data, previous hash number and the hash number of the current block
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#3941
  1. It is important that the blocks are cryptographically linked together because this will prevent a miner from changing a single transaction within a block within the blockchain.
  2. The block structure in bitcoin is the previous hash, the transactions within the block and a random number called a nonce.
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#3942
  1. The cryptographically link between blocks makes the blockchain immutable, since changing the slightest detail in an older block changes that blocks hash, and thus creaking the link between the blocks
  2. In the block there is the previous hash, list of transactions, nonce, timestamps, difficulty target, version and merkle root
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#3943

  1. Why is it important that the blocks are cryptographically linked together?
    Because the hash of the previous block is included in the new block’s hash, any alteration anywhere in the blockchain would alter the hashes of all subsequent blocks.

  2. What does the block structure look like in bitcoin?
    Transactions
    Previous block’s hash
    Nonce

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#3944

1,to prevent ,double spending and altering transactions and to make sure the blockchain stays secure
2, previous block hash,transactions in block,nonce

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#3945

  • Homework - Mining part 2

    • Why is it important that the blocks are cryptographically linked together?
      These blocks form a chain of data as an asset moves from place to place or ownership changes hands. The blocks confirm the exact time and sequence of transactions, and the blocks link securely together to prevent any block from being altered or a block being inserted between two existing blocks (immutability).

    • What does the block structure look like in bitcoin?
      Block = Prev TX + nonce+ TX

      1193×609

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#3946

  1. By combining previous hash, with the transactions and then the nonce guessed by the miner, it means editing a previous block would break the whole chain going forward. This then makes the exponential difficulty for miners to edit previous blocks and then catch up practically impossible. This is what makes the blockchain so secure.

  2. The block structure includes the hash of the previous block, a list of transactions and the nonce which needs to be guessed by miners to create the subsequent block. There is also the miners payment for attaching the block to the chain which include, inflation (BTC reward) and the TX fees which are determined by the transactions within the block.

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#3947

  1. Why is it important that the blocks are cryptographically linked together?
    It increases the security and makes it difficult to alter blocks since you would need to remine all subsequent blocks and catch up to the chain. This is only possible if you have 51% of the total hash power.

  2. What does the block structure look like in bitcoin?
    A block contains transaction, the hash of the previous block and a noce. This is combined into a hash that will be used as previous hash for the next block.

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#3948

  1. It secures the network so that is no double spending of the same UTXOs, not including transactions that don’t make sense. Also, prevents altering previous blocks within the blockchain i.e. transactions in the previous blocks, since that would invalidate the entire blockchain.

  2. It would most likely have the following; block number, nonce number, data (i.e. where the transactions are list), previous hash and hash of your new block which would be found once the nonce, the data and the previous hash are mined to give you the hash which would then be compared with the target (i.e. a specific number). If it’s lower than the target it will be accepted and the new block will be appended to the blockchain.

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#3949

  1. It is important because it makes it almost impossible to the cheat the system since math is what creates the links.

  2. The block structure consists of a list of transactions, the hash from the previous block and a nonce which is a random number generated when mining. All these things together create a block and make a new hash which is used to mine the next block.

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#3950

1 - Because the cryptographically linking the blocks secure the network. If ANY change is made to transaction on a block in the network then the hash of that block and all subsequent blocks will be altered, invalidating the entire chain, and preventing it from being accepted by other nodes.

2 - Each block contains transactions, nonce, a hash(transactions, previous hash). The first transaction in each block is the BTC reward given to the minor that added the block.

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#3951

  1. This is to protect the network. It makes it harder for blocks to be changed or modified as it would require a rehashing of all the blocks on the network. It also enhances data immutability which is a key feature of Bitcoin’s network.

  2. The block structure is illustrated by its key components: Block number, nonce, transaction data, hash of the previous block and the current hash of the block.

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#3952
  1. Why is it important that the blocks are cryptographically linked together?

To make it practically impossible to change transaction information inside of a block without then needing to change all of the information and hashes of other blocks. It removes the possibility of fraud.

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

Each block includes the nonce, the hash of the previous block, transactions and the hash of the current block

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#3953
  1. The link also is hashed thus is unique and so that if a previous block is changed, that change is transferred through the link (because the link changes) on to the next block. Thus is means everything is changed in front and there is no way to stop that. This maintains immutability.

Nonce
previous hash
block number
number of transactions
detail of transactions (who sent what to who)
block size
current target

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#3954
  1. This ensures the data will not be changed.
  2. Pervious hash, transaction list, nonce.
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#3955
  1. Why is it important that the blocks are cryptographically linked together?
    By cryptographically linking the blocks together any changes to the previous block data also effect all future blocks in the chain. This is what makes the blockchain immutable and gives the network its trust.
  2. What does the block structure look like in bitcoin?
    (Hash of Current Block)
  • Pervious hash of last transaction
  • List of unconfirmed transactions
  • Nonuce
    = Target under a specific threshold or difficulty
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#3956

  1. It is vitally important that the blocks are cryptographically linked together to ensure the blockchain’s immutability and integrity. This linking makes it mathematically and physically almost impossible for data to be changed/revised once a block is added to the blockchain. It disincentivises data manipulation once data has been validated and added to the blockchain.

  2. A block structure in blockchain consists of the following elements: previous hash (unless it’s the initial block) + transaction + nonce = current hash

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#3957

[quote=“ivan, post:1, topic:8433”]

  • Why is it important that the blocks are cryptographically linked together?
    It is important because this way you cannot double spend and you cannot change the history of the transactions.

  • What does the block structure look like in bitcoin?
    There is a previously verified block, that contains a chain of previously verified blocks, and when a miner completes the mathematical puzzle, he is able to add a new block to the chain. This continues like this, with miners adding blocks to the previous chain.

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