Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#3758

  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.

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

1 Like
#3759
  1. It is important that blocks are cryptographically linked together for the security/integrity of the blockchain. No transactions can be changed in previous blocks because it would break the link to the next block and all subsequent blocks.
    2.The block structure is based on the transactions and hash in the block plus the previous hash and the nonce that needs to be guessed. It looks like a group of square blocks connected to each other.
1 Like
#3760
  1. Why is it important that the blocks are cryptographically linked together?

This creates signatures from each new block in the chain to all blocks that came before it. If one of the blocks from further up the chain were changed, the links would no longer fit as each subsequent hash value would have to change to include the different hash from before in the header of the following block, and so on. This is important because it keeps the network secure.

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

It looks like a chain of transaction data with headers that include the previous block’s hash, new transaction list, nonce, and new hash value for the block.

1 Like
#3761
  1. It is important that blocks are cryptographically linked together because it ensures the blocks remain immutable.
  2. The block structure in bitcoin consists of the transaction, transaction counter, block header - current target and hash of previous target, blocksize, and Nuance or previous number.
1 Like
#3762
  1. It ensures that a digital fingerprint is created and provides validation, security and integrity on the blockchain.
  2. The blocks on the bitcoin network have their own hash which is a digital fingerprint of the block. They are based on all of the transactions that occurred in the block. Miners need to guess a random number known as “NONCE” inorder to successfully append a a block to the blockchain.
1 Like
#3763

  1. Why is it important that the blocks are cryptographically linked together?
    To ensure it is very difficult (almost impossible) to break any block in the blockchain.

  2. What does the block structure look like in bitcoin?
    We have hash of previous block, list of transactions, and nonce which is the puzzle miner has to solve to create new block.

1 Like
#3764

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

It ensures immutability. The blocks become unchanged; unable to be altered.

What does the block structure look like in bitcoin?

Block # > Nonce (any change here makes the has different)> TX > Hash

1 Like
#3765

Also important to note that the current block hash is also based on the previous block hash which is how blocks are linked in a chain :wink:

#3766

  1. The make sure of the integrity and security of the blockchain. As all block always contain the hash of the previous one and are link by such means that any change on previous block will break the link.

  2. The date in the block + previsous block hash and the nouce

1 Like
#3767
  1. It protects the blockchain from tampering with previously confirmed blocks and the transactions they hold.
  2. The previous block’s hash, the transaction list of the new block and the nonce which is used to derive a valid hash for the current block being appended.
1 Like
#3768
  1. Why is it important that the blocks are cryptographically linked together?

So that the network is secure because there is no (economic effective) way to change a previous block without making the rest off the blocks after that one invalid.
So you can not censor data or double spend because of the immutable nature of the blochchain.

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

hash of the block - hash of the previous block - transactionlist from current block - nonce

1 Like
#3769
  1. Why is it important that the blocks are cryptographically linked together?

It provides the security of contained data. Longest chain (longest proof-of-work) will be always chosen as valid ones.

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

Each block contains:
a) The processed transactions
b) The previous hash
c) The nonce. This is a guessed number (by a miner) that proves that new hash matches certain condition.

1 Like
#3770

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

It is important that blocks are cryptographically linked in order to secure the network. Since the hash of each new block that is added to the chain is based on the hash of the previous block, the entire block chain can be verified. If the contents of a previous block are changed all subsequent blocks are invalidated and must be mined again.

What does the block structure look like in bitcoin?

Bitcoin’s block structure consists of transaction data, the hash of the previous block, the nonce and the hash of all of these.

1 Like
#3771

  1. it is important that the links are cryptographically linked to keep the blockchain secure and immutable.

  2. Block Structure:

    • Block #
    • Nonce
    • Transactions
    • Previous Hash
    • New Hash
1 Like
#3772

1- Provides incentive to remain honest and not delete or alter transactions.

2-Transactions, Hash, and Nonce

#3773

What hash? :stuck_out_tongue:

#3774

  1. It is important because it helps keep the network secure. If someone was to change the contents of a block on the blockchain, they would need to cryptographically solve all the subsequent block’s hashes, which would be incredibly difficult and expensive.

  2. A block contains a list of transactions. On top of that, it contains a hash that is based on a nonce, the transactions in the block, and the hash of the previous block, which needs to be lower than the target set by the network.

1 Like
#3775

  1. Because it makes people incentivized to play by the rules and not break them otherwise the whole chain will fall apart.

  2. Each block is made up of transactions, nonce and the hash of the previous block.

1 Like
#3776

  1. It ensures immutability. You can’t chance a single thing without breaking the blockchain.

  2. Block size + nonce + TX counter + current target + previous block’s hash

1 Like
#3777

  1. Why is it important that the blocks are cryptographically linked together?
    To secure the network to prevent no double spend and altering of previous transactions.

  2. What does the block structure look like in bitcoin?
    Nonce
    Transaction
    Previous hash
    The current hash block is determined by these factors.

1 Like