Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4098

The cryptographic link ensures that if any of the data in any block is changed it will change the hash of every linked block. this keeps the chain secure and visibly easy to verify.

Block structure consists of the block size.
A block header which contains, previous blocks hash, hash of blocks transactions, a timestamp, and nounce.
Transactions and transaction counter.

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#4099
  1. Because they can not be changed.
  2. The block that is mined depends of the last mined block. So, it is a linear structure.
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#4100
  1. It is to keep the blockchain together, making it more secure as well as avoiding double spending.
  2. In the block there are previous hashes, the transactions as well nonces. The block after that has the hash relaying all of that.
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#4101

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    *Without hashing bitcoin will not exist. It makes the data secure

  2. What does the block structure look like in bitcoin?
    *It contains the transaction data of the current block, hashed of course. It also contains the hash of the previous block and the nounce.

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#4102
  1. Why is it important that the blocks are cryptographically linked together?
    • Creates difficulty to change previous Tx
      • Incentivised being honest
    • Blocks remain immutable
  2. What does the block structure look like in bitcoin?
    • Previous Block Hash
    • New TXs
    • Nonce (guess)
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#4103

  1. To find the answer to the puzzle, a number lower than the set target, you use current unvalidated transactions plus the outcome of the puzzle of the previous block plus a nonce. You hash this and it gives a unique number. If you leave out the outcome of the previous puzzle in the current puzzle, you can potentially change transactions in the previous block without an effect on the chain.

  2. In a block, you have among other things like a timestamp, the previous hash, unvalidated transactions and a nonce.

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#4104
  1. To prevent transactions being changed in previous blocks. Allows data to be secured once confirmed.
  2. Block structure consists of transactions, previous block hash and nonce number.
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#4105
  1. Why is it important that the blocks are cryptographically linked together?
    So that if anything is changed in a previous block, it will affect all subsequent hashes which alerts the network that something has been tampered with.
  2. What does the block structure look like in bitcoin?
    Block
    Data
    Nonce
    Previous Hash
    Current Hash
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#4106
  1. Why is it important that the blocks are cryptographically linked together?

As blocks are linked together it creates a continuous and structured puzzle that show their “fingerprints” and harder to change one single block within the change.

  1. What does the block structure look like in bitcoin?
    The block structure mainly consists of a previous block has, a list of transactions inputs and outputs, and a nonce that is continuously guessed until it is less than its target
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#4107

  1. Why is it important that the blocks are cryptographically linked together?
    Ans : Coz by cryptographic the data are encrypted. So no one can get the data by using hash .

  2. What does the block structure look like in bitcoin?
    The combination of index, timestamp, previous hash, block data, and nonce

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#4108

  1. Its important that the blocks are cryptographically linked together so it adds that base security that blockchain theory operates on – each block is a copy of the past so it blocks against all sort of scams and frauds and makes everything transparent.

  2. The block structure in bitcoin shows the hash of the block in the transaction and input and output the nonce and etc.

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#4109

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

    The fact that the blocks in a blockchain are cryptographically linked together provides security in that when one block is changed it causes all other blocks after it to have their fingerprints or hashes altered also.

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

block header
block size
transactions
nonce
prev block hash

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#4110

1.) This achieves that you cannot just add one false block to the chain as a bad actor, because if you create one false blocks, you’ll have to also create false consecutive blocks, since the correct ones will not fit the new false one prior to them. Having to create a whole false chain disincentivises such attempts of counterfeiting the blockchain.
2.) A block consists of the nonce, the transactions, and the hash. The hash is linked to the hash of the previous block.

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#4111

  1. It makes it difficult to change a block. You have to create hashes between the blocks.

  2. Previous block --> transaction --> nonce.

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#4112
  1. This maintains the security of the network. There’s no way blocks can be changed because it would break the link between each block. There is no incentive to change the blocks.
  2. Hash of the previous block, transactions, nonce, hash of current block.

Ps Can someone please send me the link of where to mine BTC like in the video in the course.

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#4114

1 So it will be nearly impossible to change previous transactions because remining all blocks since the changed block is time and cost prohibitive.

2 The hash of the previous block, the current block transactions and the target nonce of the block

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#4115

  1. Because it makes it almost impossible to change previous transactions beacuse of the hashes created.

  2. Previous hash, transactions & nonce.

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#4116

  1. Because it ensure that the blockchain will stay inmmutable.

  2. Like a sucession of different blocks linked by cryptography which can not be changed without altering the rest of infomation in it. In bitcoin the information is the transactions.

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#4117

  1. Why is it important that the blocks are cryptographically linked together?
    This creates a strong layer of security for the blockchain as if any minute detail is changed the rest of the chain henceforth now is changed and would need to be re mined.

  2. What does the block structure look like in bitcoin?
    Each block contains previous hash from the block right before it, a list of transactions, and a nonce or random number miners are trying to guess.

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#4118

1). Blocks must be linked together cryptographically as the previous hashes play an integral role in the hash of the newest block that is about to be mined.

2). The block structure is:
Prev. Hash.
TX list.
Nonce.

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