Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#2854
  1. Why is it important that the blocks are cryptographically linked together?
  2. What does the block structure look like in bitcoin?

1 - So when you solve the crytographyc puzzle you create a link . The links between block are expensive and they are not just a random connection . They are very special , because they are based on the information from the previous block and it linked all blocks together.
2. The structure of a block contains the list of transactions , the hash of the previous block and the nonce.

1 Like
#2855
  1. Blocks are cryptographically linked, to maintain an immutable audit trail / track, across all the blocks in the blockchain
  2. The block structure in bitcoin starts with a Header that contains (1) The hash of the previous block (2) The hash for all transactions within the block (3) The Nonce hash. The header if following by the list of individual Transactions within that block
2 Likes
#2856

1. Why is it important that the blocks are cryptographically linked together?
To ensure that the transactions won’t be able to be changed because each link (puzzle) is based on the previous block. It is impossible to break one link because then all the links and blocks would be broken and that is impossible due to the hash rate.

2. What does the block structure look like in bitcoin?
Each block information is based on the previous blocks. The puzzle is based on the content of previous blocks. When one of the miners is able to solve the puzzle, his block will be accepted, and a link will be created. This link is based on the puzzle. The links between blocks are expensive and special. They are based on the information on the previous blocks. This makes is so that if I were to try and remove a transaction, the link would be broken, because the puzzle (link) is based on the previous blocks. If a link were to be broken, then all links would get broken. And that is impossible, because it is proportional to the hash rate.

1 Like
#2857

Homework on Blockchain and Mining Visually - Questions

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

To ensure that all blocks remain immutable.

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

The block is made out of data, previous block hash and a nounce, which is used to calculate a hash number below a threshold (difficulty).

1 Like
#2858
  1. To persist the data in a way that the simplest alteration of past data would break the validity of the blockchain.
  2. It is based on the hash of the previous block, the current transactions and a nonce that needs to be guessed.
1 Like
#2859

1- the blocks need to be connected and follow the good practice, rules and structure with miner integrity so this provides a secure and anti censorship of the protocol.

2 Every block is based on the (previous block’s harsh + TX List + Nonce).

1 Like
#2860

Answers to “Blockchain and Mining Vissually” Questions:

  1. To make the network extra secure. It would be extreme hard to modify a block, because the other block hashes wont match anymore.

  2. block contains: previous hash, Tx List, nonce

1 Like
#2861

  1. Cryptographically linking together the blocks ensures the security and integrity of the blocks since it is impossible to change any data on any one block.

  2. In bitcoin the block structure or the hash is a combination of the nonce, the transaction data and previous hash.

1 Like
#2862
  1. the network can never be changed
    2.Tx, nonce, Prevous UTXO, hash
1 Like
#2863
  1. It is for security reason. When one block is altered, all chains link to the blocks after it will be broken, rendered untruthful.
  2. A block includes nonce, transaction, previous hash, and current hash.
1 Like
#2864

  1. Because if you changed any block you would have to rehash every single block that was created afterwards.

  2. TX list, Nonce, Previous hash

1 Like
#2865

  1. It is important that blocks are cryptographically linked together to provide security and integrity. It becomes impractical to modify past data.

  2. The block structure contains the transaction data, the hash of the previous block, and a nonce.

1 Like
#2866

  1. Hashes secures the blockchain by being immutable, and disallows double spending giving the chain integrity.

  2. Block structure the hash of the previous block is then added too with a new transaction and a nonce, all of which are then hashed again to creat the new block!

1 Like
#2867

  1. makes it impossible to alter data on a previous block which would stop things like double spending etc.

  2. Each block has the hash, transactions and nonce from the previous block

1 Like
#2868

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

This feature of the blockchain is how we identify Proof of Work. WIthout this feature the blockchain would not be secure.

What does the block structure look like in bitcoin?

Structure of a block

Block Header:

  • Verion
  • Previous Block Hash
  • Merkle Root
  • Timestamp
  • Difficulty Target
  • Nonce
    Transaction Counter
    Transactions
1 Like
#2869
  1. Why is it important that the blocks are cryptographically linked together?
    To make sure the the blockchain is safe and that there is no change in previous blocks possible.
  2. What does the block structure look like in bitcoin?
    Every block includes the transaction data (list) and the previous block’s data hash
1 Like
#2870
  1. Because the security is very high. In order to change some transaction in a previous block you have to change all other blocks and hashes that follows because all are connected.
  2. The block structure contains the hash of the previous block, the list of the transactions and the nounce. All these will generate a new hash that has to be lower than the target. If the hash is lower than the target then the block is accepted.
1 Like
#2871

1, Block links are linked together with a difficult to solve mathematical puzzle, this makes it more difficult to backtrack and change a previous block.
2, Blocks are based on 3 things - Half of the previous block, list of transactions & nonce

1 Like
#2872

I think you meant hash? :smile:

1 Like
#2873

fat fingers :frowning:
correct thanks.