Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#2694

  1. It ensures the security of the blockchain network. If one transaction is changed it would unlink all the following blocks. This way it insures the blockchain.

  2. The block is made of a previous hash, the transaction list and the nounce. Which means the the hash of the block is made of all these datas.

1 Like
#2695
  1. Why is it important that the blocks are cryptographically linked together?

It is important because of the hash functionality between the blocks.

  1. What does the block structure look like in bitcoin?
    A block is a container data structure that aggregates transactions for inclusion in the public ledger, the blockchain. The block is made of a header, containing metadata, followed by a long list of transactions that make up the bulk of its size. The block header is 80 bytes, whereas the average transaction is at least 250 bytes and the average block contains more than 500 transactions. A complete block, with all transactions, is therefore 1,000 times larger than the block header.
1 Like
#2696

1: This link is the ā€˜unbroken chainā€™ that adds value to a blockchain system. The longest unbroken chain is always the correct chain that is built upon. By including cryptographic hashes of the previous block, it is immediately possible to notice when data in the chainā€™s history has been changed

2: Current block is comprised of Previous Blocksā€™ Hash, current tx list (data) and the Nonce hashed to produce a result less than the target.

1 Like
#2697

  1. Why is it important that the blocks are cryptographically linked together?
    To prevent altering the confirmed transactions in the blockhain.

  2. What does the block structure look like in bitcoin?
    Block Hash {
    Nonce (random number)
    Hash (hash of previous block)
    Data (list of transactions)
    }

1 Like
#2698

  1. Why is it important that the blocks are cryptographically linked together?
    It ensures the integrity of the blockchain and that transactions are valid and canā€™t be compromised. Itā€™s what contributes to the ethos of a trustless open entity with no central authority that can intervene. For miners it means that remining previous blocks isnā€™t required as the chain is complete and meets all criteria to incentives the miner.

  2. What does the block structure look like in bitcoin?
    Block number
    Nonce
    Transaction Data
    Hash of the Previous Block
    Hash of current block

1 Like
#2699

  1. To increase the security, the difficulty changes exponentially the further back in the chain you intend to do the change.

  2. the hash of the blocks are based on previous hash, transactions list and a nonce.

1 Like
#2700

  1. the blocks all carry the transaction hash from the previous block, creating a digital finger print. Which allows each block to be verified on the chain.

  2. hash of previous block + any transaction data + nonce < target

1 Like
#2701
  1. Why is it important that the blocks are cryptographically linked together?

Iā€™ts important that the blocks are cryptographically linked together to maintain the security of the system. If blocks are together, it means a hash containing the current and previous blocks were verified. No changes can be made on the previous blocks and therefore would confirm that a transaction indeed took place and no changes could be made by anyone or any entity.

  1. What does the block structure look like in bitcoin

a block structure consists of the previous hash, the current transactions in the new block to be created and a nonce.

1 Like
#2702
  1. it makes changing something in previous blocks more difficult
  2. previous blocks hash, data of current block and nonce all together create a hash of the current block
1 Like
#2703
  1. It keeps the system safe from being tempered with making it unchangeable.
  2. it looks like table with columns and lines which contains encryptions, transactions, numbers and so on.
1 Like
#2704

  1. Why is it important that the blocks are cryptographically linked together?
    It provides security and integrity to the network.

  2. What does the block structure look like in bitcoin?
    Each block is composed of the previous hash, the transaction list and the nonce.

1 Like
#2705

  1. By cryptographically linking the blocks together, the security of the network is maximum because changing data on previous blocks would be practically impossible. Even if somebody tried to do that, all nodes of the network would keep working as normal on the longest chain available and those blocks would all be refused.

  2. In bitcoin, blocks have mainly 3 components :
    -Hash related to that specific block generated by a list of transactions that the
    miner used to create that block
    -Nonce number (the ā€œtargetā€)
    -Hash of the previous block

1 Like
#2706
  1. Why is it important that the blocks are cryptographically linked together?

It is crucial to the nature of how the blockchain works, how it will be upheld and continually built upon by the miners, and how it will be secured from malicious miners trying to alter previous transactions in the blockchain.

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

The block structure in bitcoin contains a transaction list, a hash from the previous block, and a nonce (random number). All of this data must be hashed to find a hash lower than a target number in order for the block to enter the blockchain. The nonce is the variable that must be changed over and over in the guesses in order to find the correct hash.

1 Like
#2707

  1. Itā€™s important because it helps to prevent the data from being altered.

  2. Previous block hash, Txs list , nonce, block size, block header, timestamps and target.

1 Like
#2708

1- It gives integrity to the blockchain, it ensures that there are no changes in the history of the transactions and ensures also that there isnā€™t double-spending
2- Previous Hash, Transactions list, and NONCE

1 Like
#2709
  1. because of safety (secures against incorrect transactions)
  2. hash number from previous block, hash of this block, nonce No, list of transactions
1 Like
#2710

  1. Why is it important that the blocks are cryptographically linked together?
    Because each block links to its predecessor, data in the blockchain is immutable.

  2. What does the block structure look like in bitcoin?
    The Block size.
    -The new hash with all the transactions,
    -The previous hash.
    -The difficulty target,
    -The nonce

1 Like
#2711
  1. the links provide additional security - each blockā€™s hash is based on the previous block as well as the link
  2. boxes with data
1 Like
#2712

  1. Linking the blocks together cryptrographically increases the difficulty of altering previous blocks. The difficulty (spent energy and time) to rehash increases with distance from current block, because each removal adds not only 1 more block to rehash, but also the new blocks being hashed currently that will need to be caught up to and surpassed in order to have a blockchain long enough to be accepted. This makes the blockchain functionally immutable and secure.

  2. Each block contains the hash of the previous block, the transactions being included in the current block (inputs/outputs), and a nonce.

1 Like
#2713

  1. Blocks are cryptographically linked together so that the chain cannot be broken.

  2. A block is comprised of a nonce, the transaction data, the hash, and the hash of the previous block.

1 Like