Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#685

  1. It shows that the blockchain is secure plus too hard to undo.

  2. It has Hash of the block and previous Hash, nounce and data.

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#686

  1. Its a security protocol. Meaning that by changing a hash in a previous block, you will need to change the hashes for that and all future blocks until the last one in order for the whole network to approve this change in the blockchain.

  2. The cryptographic hash (fingerprint) of each new block is based on:
    a) the hash of the previous block
    b) the data (for the transactions included in the block)
    c) Nonce (the random number puzzle)

  • a+b+c will create a unique has that will then be used in the next block. Thus creating a link between blocks.
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#687
  1. Why is it important that the blocks are cryptographically linked together?
  • To ensure the blockchain remains immutable. If you change info in one block it will effect all the following blocks erasing their PoW.
  1. What does the block structure look like in bitcoin?
  • Hash = sha256(Previous hash + transactions + nonce)
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#688
  1. This is like a security layer because if you change one block you will need to change all the blocks because a new hash will create into a block and this new hash will not have relations with the other blocks.
  2. Previous block hash, and a nounce, data, block number (header) and new hash.
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#689

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

This is important because it makes it impossible to change one block without breaking the link by changing the following blocks in the chain. This makes it practically impossible for someone to double-spend, or create BTC out of thin air.

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

Each block’s hash consists of the list of transactions in the block, the hash of the previous block, and the nonce.

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#690
  1. Why is it important that the blocks are cryptographically linked together?

It is important that blocks are cryptographically linked together for the security of the blockchain. That way no transactions can be changed in previous blocks because it would break the link to the next block and all that follow.

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

It consist of the hash of the previous and current block, list of transactions, nonce, amount of transactions, summaries, fee, times, sizes, version and reward.

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#691

  1. Cryptographically linking the blocks together makes it harder to change the information in a block because you would have to solve the new hash algorithm for the block and all the blocks that come after it. This ensure that no alterations or corruptions or hacking can come to the data.

  2. The block is made out of transaction data, the previous block hash and a nonce.

#692

*Once the blocks are cryptographically linked they are securely verified and any changes will break the links in the blockchain. This would then be breaking a rule and the miner would not be rewarded for the transaction.
*The block structure consists of the previous block’s hash, the existing block’s hash, a list of transactions and the nonce code.

#693
  1. Its important that the blocks are cryptographically linked together to make the blockchain network secure. If someone changes something in the previous blocks it would fail in all the following blocks.
  2. The hash is based on the transaction in the previous block and the nonce that has to be guessed.
#694

  1. It is important that blocks are cryptographically linked together because this ensures the security of the network. It means that you can’t just solve the puzzle for a single block. Accessing one block requires solving the cryptography in all the connected blocks as well.

  2. The blockchain in bitcoin looks like a linked list with the all the hashes and previous transactions, and (now) 6.25 BTC being released in each block.

#695
  • Why is it important that the blocks are cryptographically linked together?
    Because they need to be secure. It ensures the integrity of the blockchain and makes it mire reliable.
  • What does the block structure look like in bitcoin?
    The block is linked to the previous hash and block, transactions and nonce, which generates a random number which is used to try and get the hash low enough to be accepted
#696

  1. Why is it important that the blocks are cryptographically linked together?
    To ensure integrity of the blockchain

  2. What does the block structure look like in bitcoin?
    the nonce
    transactions
    hash of the previous block
    hash of nonce, transactions and previous hash

#697
  1. It helps to keep the network secure and nobody can temper with the data (immutabilty).
  2. The hash of the new block is based on the previous hash + transactions +
    nonce number the miners need to guess.
#698
  1. Why is it important that the blocks are cryptographically linked together? Cryptographically linking the blocks insures immutability. Changing anything in one block changes all following blocks.
  2. What does the block structure look like in bitcoin?
    Bitcoin blocks contain the TX data, the hash of the previous block, and a nonce.
#699

  1. By cryptographically linking blocks together it makes in virtually impossible to cheat the system. Each block uses and is created from information (Hash) from the previous block, and the next block along the line is created off the current blocks hash. If you try to amend a block, you will break all links to other blocks and will be isolated from the network.

  2. A block is made up of TXs, the previous hash and a nonce (number to be guessed) Those 3 components make up the new hash.

#700

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

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

1)Because its a digital ledger that cant be altered.

2)Each block contains, among other things, the current time, a record of some or all recent transactions, and a reference to the block that came immediately before it. It also contains an answer to a difficult-to-solve mathematical puzzle - the answer to which is unique to each block.

#701

1)so manipulation trials can be identified, because the block connecting hash has been altered. therefore we can trust without a central party, that data inside the blockchain is trustworthy and not manipulated
2) transaction data, previous block hash, block hash

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#702
  1. Why is it important that the blocks are cryptographically linked together?

Is important because in this way no transaction can be changed in the previous block as this will break the link between blocks. All this make the network secure and makes the miners to play by the rules.

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

The structure of a block in bitcoin contains the list of transactions, the hash of the previously mined block and the nonce, which is essentially a random number which is used to try and get the hash low enough to be accepted.

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#703

1.To secure Blockchain network.

  1. The block structure contains - previous hash, tx data, nonce and current hash.
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#704
  1. Why is it important that the blocks are cryptographically linked together?
    Because when they are linked together is impossible to go back and change data in the previous blocks .The chain will be broken and the links between the blocks too
  2. What does the block structure look like in bitcoin?
    Block number, Nonce , previous hash , transaction data and the new hash for the next block
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