Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4502

  1. Why is it important that the blocks are cryptographically linked together?
    So that there is certainty and integrity to the blockchain status. Therefore no one can tamper the previous blocks and create double spend.

  2. What does the block structure look like in bitcoin?
    It is composed of the previous hash, the data of our transaction and the nonce, which is random number assigned to us once we mine transaction. This new hash will become the previous hash of the transactions, and so on.

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#4503

  1. Helps prevent data from being altered. Ensures blocks remain immutable.

  2. Transactions, blocksize, block header, hash of previous block

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#4504

  1. to provide more security to the chain

  2. A tx, the inputs and finally outputs

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#4505

1 because nothing can be change in the past without changing the whole chain

2 it is a bunch of transactions with the hash of the previous block, a nonce, and the hash of the present block

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#4506

1.) its a math puzzle that has to be linked between blocks or then its not validated.
2.) hash: previous hash+current hash+random number(nonce)

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#4507

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

    • A: Because of the reference they have to each other. If one block is modified the next blocks reference of the previous block will not match and thus the link get’s severed. This safety mechanism prevents double spending and makes the blockchain very secure.

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

    • A: It consists of the following
      • The Nonce #
      • Data: Essentially all the transactions
      • The previous hash reference
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#4508

  1. If the blocks are not linked together it would be possible to a an attacker to changes transactions in the network without breaking the chain.

Block Identifiers
Block Header
Transactions

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#4509

1. Why is it important that the blocks are cryptographically linked together? Part of the structure of a block in a blockchain is the hash from the previous block. If the blocks were not linked, error free transmission of this hash from the previous block would be more complex. More importantly, if the blocks were not linked together, someone with bad intent could re-mine a single block without having to worry about re-mining the later blocks (making it easier to corrupt the system). This would probably not be a blockCHAIN.

2. What does the block structure look like in bitcoin?
Block structure: hash of previous block - transaction list of current block - nonce. The result of the combination of these three components must be a hash that is less than the target value.

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#4510
  1. It’s important for blocks to be cryptographically linked together for security measures. IT ensures that no data in the transaction list can be changed in the current, or the previous hash functions of the blocks in the blockchain.
  2. The block structure is basically a list of transanction datas that are grouped into blocks which are created by miners and they also contains nonces. Nonces are random combinations of unmbers and letters which miners are trying to guess while being under the set target. The blocks are linked through cryptograpric calculations using the hash functions.
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#4511

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    To reach consensus consistently.

  2. What does the block structure look like in bitcoin?
    Previous Hash + Transaction + Nonce = Current Hash

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#4512
  • Why is it important that the blocks are cryptographically linked together?
  • because they’re transactions, this is to ensure the ledgers are correct vs accounts/wallets
  • What does the block structure look like in bitcoin?
    Block Number > Nonce > Transaction Data > Hash of the Previous Block > Hash of the current Block
1 Like
#4513

  1. Linking the blocks together ensures the immutability of the blockchain. Any attempt to change a previous block destroys the links of subsequent blocks. Cryptography means that secretly remining all those blocks is not possible.

  2. A block in bitcoin contains a list of transactions, the hash of the previously mined block and the nonce, a random number that is used to get the hash lower than the target.

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#4514

  1. Why is it important that the blocks are cryptographically linked together?
    A// It is important that the blocks get cryptographically linked together because this first ensure a more secure network and to no make a doble spend

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

-HASH

-PV HASH
-TX
-NONCE

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#4515

  1. This ensures immutability which is fundamental to a decentralised network.

  2. Each block contains data that includes the previous block’s hash, transaction list, nonce and current block hash.

2 Likes
#4516

  1. That is a way to ensure that the integrity of the chain is maintained. It ensures that all data is kept in the correct sequence and to ensure nothing can be altered.

  2. Hash of previous Block + TX List + Nonce = new Block Hash

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#4517
  1. Why is it important that the blocks are cryptographically linked together?

Answer: this mechanism ensures security and safety of the network, making it impossible for participants to alter transactions in already mined blocks.

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

Block structure goes as following:
block number
previous hash
nonce
TXs list
block hash

  • some other metadata (it wasn’t mentioned in the video)
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#4518

Homework on Blockchain and Mining Visually:

  1. When all blocks within the blockchain are cryptographically linked together, it eliminates fraud and/or untruthful transactions. Making this attribute extremely important towards the immutability of blockchain.

  2. Block number
    Nonce
    Transactions
    Previous block
    Hash

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#4519

  1. without the link it would be easier to change data of previously mined blocks.

  2. it consists of transaction list, previous blocks has and a nonce, which is a random number guessed by the miner.

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#4520

  1. It helps us to secure the network. You can’t make a change in the past easily.

  2. A block consists of the hash of a block consisting of the hash of the previous block, tx lists, and the nonce.

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#4521

  1. It is important that they are all linked because that is the backbone of the the technology and securing the network. This ensures that no one can change the previous data because all blocks will are based on the data in the previous block.

  2. The block structure is SHA256(data) = hash. The structure of the block changes as data is input but once the block is verified and mined that data is there forever!

1 Like