Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#1667
  1. Why is it important that the blocks are cryptographically linked together?
    To ensure the integrity of the blckchain, such as avoid douplbe spending and immutability
  2. What does the block structure look like in bitcoin?
    Miners hash the current block base on hash of previous block, transaction list and nonce
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#1668
  1. The blocks should be linked together to ensure the security of the network
  2. A bitcoin block include:
  • Time stamp
  • index
  • Data (Transactions)
  • hash of previous block
  • nonce
  • Hash of current block
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#1669
  1. So that it is really difficult to change the data of previous blocks. This promotes stability within the system.
  2. Each block has the current hash, the hash of the previous block, the nonce, and the transaction list.
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#1670
  1. This is important because as the size of the chain is longer the desire to try to change a block in the block chain is reduced. If a persons block on the block chain is unlinked they lose all incentives for creating the block. They will also lose the ability to continue to mine because their copy of the block chain will continue to be invalid to the other miners copies which will not allow any future attempted acceptance of their mined block being accepted into the blockchain.

2.from upper level to lower level:
Hash of the current Block --> (block contains Current transactions hash + Previous Block transactions hash + NONCE)

This is how it looks on the bitcoin explorer:

Hash 00000000000000000007c9ed0e7521f27fcabb05cbfb5f1246bc7677e992df79

Confirmations 1

Timestamp 2020-09-06 22:41

Height 647067

Miner SlushPool

Number of Transactions 1,842

Difficulty 17,557,993,035,167.31

Merkle root 55a0363047dd7df9857867f54d57baed808d16357e8a8a6145d0df7e805b0b85

Version 0x3fff0000

Bits 386,926,570

Weight
3,993,459 WU

Size

1,189,743 bytes

Nonce 343,978,963

Transaction Volume 1781.83834470 BTC

Block Reward 6.25000000 BTC

Fee Reward 0.13062224 BTC

Learn more about how blocks work.

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#1671

  1. This ensures that past transactions can not be altered. Everything recorded in the blockchain is immutable.

  2. Block structure in bitcoin contains a:

  • Size of the block
  • Header with hash of previous block / Timestamp
  • Merkle tree
  • nonce
  • transaction counter
  • Data block with all transaction
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#1672

  1. Being linked together makes it safer to use the bitcoin network for transactions, by being linked together it makes it almost impossible to go back and tamper with or change data in a previous block which would require massive power and wouldnā€™t be profitable for the person doing it.

  2. Previous hash, transaction list and a random number called nonce.

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#1673
  1. Why is it important that the blocks are cryptographically linked together? To ensure network security and immutability, preventing bad actors from manipulating transactions on the blockchain.
  2. What does the block structure look like in bitcoin? Basic block structure includes the previous blockā€™s hash, the currently mined blockā€™s transaction list, and nonce.
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#1674

Oh buy a Coinmine one miner and has some fun. :grinning: Cheap, energy efficient, and you join a larger mining pool. Very simple deviceā€“plug in and mineā€¦ Seriously, it is that easy. No, it wonā€™t make you a millionaire (maybe, who knows) but ā€œall good things to those that mine.ā€ I think it was Lady Mary Montgomerie Currie also known by her pseudonym Violet Moto Fane Toshi. Kidding. She was actually a very profound poet and illustrator and a woman battling the whirlwinds of her timeā€“very Nakamotorized,imo.

  1. The blocks are cryptographically chained together because it is a blockchain. If one block is altered then it is ā€œdecoupledā€ from the rest of the chain. In this regard, the links in the block chain ensure the strength of the transactional history in the chain itself.
  2. Nonce, data, previous hash, hash-- red, mine, green and POW!
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#1675
  1. It is important that the blocks are cryptographically linked together so that miners cannot alter transactions in previous blocks without the links being broken.
  2. The block structure in bitcoin looks like the block number, the list of transactions, the nonce, the previous hash, and the hash of the current block.
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#1676

  1. Why is it important that the blocks are cryptographically linked together?
    A: This creates a trustless system by creating immutability. If one block is amended, this in turn would cause all other blocks to change. This also prevents double spending.

  2. What does the block structure look like in bitcoin?
    A: Block Number
    Nonce
    Data
    SHA-156
    Previous Hash
    Hash

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#1677

Security and data integrity.

The previous hash and the current hash, the transactions, block number and the nonce number

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#1678

  1. Why is it important that the blocks are cryptographically linked together?
    To ensure that the previous agreed blocks will be nearly impossible to be modified, and hence maintain the security and stability of the blockchain.

  2. What does the block structure look like in bitcoin?
    It contains
    (i) a list of transactions,
    (ii) the hash value of the previous block,
    (iii) nouce, and
    (iv) the hash value of current block

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#1679
  1. The blocks that are cryptographically linked can verify the data integrity of the blocks and protect it from any change. The links that connect the blocks are a series of digital fingerprints that not only represent the block it points to but also a snapshot of all blocks linked up to that point(from genesis block). It is impossible to alter any data without detection. Any change to a linked block will trigger a domino effect that changes the values of all subsequent blocks. When this happens, those blocks will become invalid as itā€™s conflicting with the original version and did not go through network validation.
  2. Bitcoin Block has a block header and transaction data. The block header contains data like previous block hash, Merkle root hash, target difficulty and the nonce.
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#1680

  1. Linking the blocks together ensures immutability, and provides security to the network.

  2. The block contains the hash of the previous block, the transactions in the block, and the nonce.

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#1681
  1. Its important because if anyone tries to cheat the system, it will set off the chain reaction of errors on each following block that then they would have to change as well.
  2. Each block has a hash of its transactions, a hash of the previous block and a nonce. When all hashed together and if hit below the target, that hash then becomes the hash of the new block.
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#1682
  1. Why is it important that the blocks are cryptographically linked together?

This ensures that blocks are linked together via a chain, hence blockchain. An altercation of any block within this chain would result in changes of the hash of subsequent blocks and thus it is infeasible for a blockchain to be created that has had its past altered, whilst being the longest chain at any one given time in the system.

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

A block consists of to-be-confirmed transactions, the hash of the previous block, and a randomly guessed nonce by the miner.

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#1683

  1. Why is it important that the blocks are cryptographically linked together?
    It is to maintain the integrity of not only the current block, but also the blocks that came before and the blocks that will be produced in the future. When every block in the blockchain is connected, it makes it significantly harder to change anything in a block because they too have to change everything in the blocks that come after it.

  2. What does the block structure look like in bitcoin?
    A block has a the hash of the previous block, the transaction data (input and output) in that block, the nonce that needs to be guessed, and the new hash generated by that block to connect with the next block. Within the transaction data, there will be all the transactions that the miner has selected to be included in the block, along with the block reward (which consists of the inflation rate or newly generated bitcoin and the transaction fees collected from all the transactions included in the block).

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#1684
  1. When blocks are cryptographically linked together we ensure immutability by intrinsically linking the blocks together using the hash of the previous block to create the hash of the current block. This is important because it prevents things like double spend occurring.
  2. The block structure in bitcoin looks like the following:
    1. The Block Size
    2. The Block Header (version, previous block hash, merkle root, timestamp, difficulty target, nonce)
    3. The Transaction Counter (how many txā€™s follow)
    4. The Transactions
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#1685
  1. They need to be linked together for the security of the chain making it harder and more expensive to try and change.
  2. Inputs, outputs, and previous hash
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#1686

  1. It is important that the blocks are cryptographically linked together so it is not easy to change or delete something. It makes blockchain immutable and reliable.

  2. Block contains from hashed transactions, nonce and previous blocks hash.

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