Homework on Blockchain and Mining Visually - Questions

  1. So the miner that finds the last block cannot go and change transactions in the previous blocks without “getting caught”
  2. The block is a list of transactions, the first transaction is always the mining block- and transaction fees reward
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  1. It is important because it provides security in which previously linked blocks cannot be changed.
  2. The block structure is the previous hash, transactions, and nonce; which all together determines the hash of the current block.
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  1. To ensure immutability and previous data couldn’t be altered
  2. Combined the previous hash and transaction data with the nonce makes the new hash
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  1. Why is it important that the blocks are cryptographically linked together?

Because they cannot be attacked easily by any dishonest miner, all the blocks are linked to the previous block so that if any of the hashes and information change, the complete network will be broken and the rest of the miners will not validate those fake transactions.

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

Hash, previous block hash, nonce, transactions information.

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It also contains a few other parts, the important ones to mention are the previous block hash and a nonce :slight_smile:

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  1. So that it is harder to break the connect.
  2. The hash number of the current block is based on the hash number of the previous block, the current block’s transaction and nonce.
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  1. It is important to cryptographically link the blockchain because it enhances security making it more difficult to change and amend activity on the network.

  2. The structure of a blockchain has input and out, txt hash, block size, transactions, nodes, Nonce, merkle roots hash and network

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  1. Because this is what ensures that once a block is created, it can’t be erased or modified in any way. Since each block contains a hash of the previous block, changing anything in one block requires re-mining every block after it.

  2. It’s a string of blocks which contain a hash of the previous block, a nonce, and a list of data (transactions).

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Homework on Blockchain and Mining Visually - Questions

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

so that there is a layer of protection against possible malicious modifications of individual blocks.

  1. What does the block structure look like in bitcoin?
    -timestamp
    -nonce
    -previous hash
    -list of transactions
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  1. Linking blocks together through hashes ensures the security of the network/database.
  2. Blocks contain a set of transactions that are sealed and linked together by a hash that is generated from the previous block’s hash and the tx’s of the current block.
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blockchain security

block number
nonce
transaction data
hash of previous block
hash of current block

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  1. It is important that all blocks be linked together cryptographically so that no one can go and modify any part of the existing blockchain

2.A block in bitcoin consists of

  • the hash of the previous block
  • a list of transactions
  • the nonce which solves the current mining target
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  1. The reason that the blocks are photographically linked together is to make it impossible to change, modify or erase any data, because that would break all the chains and blocks following the modified one.

  2. The block structure: previous hash, transactions list, nonce (which is random number that creates a hash number lower than the target number in order to be accepted)

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  1. Blocks are linked together to insure trust and security on the data.

  2. The block structure has these components; header, previous block hash, transactions within block, nonce, new hash.

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  1. The links between the blocks make the database immutable, and provide apart of the puzzle (via the hash) that miners must solve for the next block.

  2. Inputs and Outputs (UTXOs and History)

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This is only the transaction, there is other data included in a block, most important is the hash of the previous block. :slight_smile:

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  1. That ensures that if a block is changed all following blocks will be changed as well
  2. each block contains the hash of the previous bloc, all tx’s and the nonce
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  1. Why is it important that the blocks are cryptographically linked together? It keeps everything immutable and as a digital stone
  2. What does the block structure look like in bitcoin? The block structure of bitcoin includes the nuance, data(transactions), previous hash, and current hash
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  1. It’s important that blocks are cryptographically linked together because it makes it nearly impossible for information to be changed on previous blocks. This increases the overall security of the blockchain.

  2. The hash of the current block is based on the transactions, the previous block’s hash, and the nonce (which is the number miners need to guess).

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  1. Cryptographically linking the blocks together creates immutability of the entire chain --> if one block is altered, then the rest of the blocks in the chain are then altered and the network will reject the new chain. This provides security to the network.

  2. The blockchain follows a linked list data structure in which data inputs (the transactions) are organized into a merkle tree, which each leaf being hashed into higher orders up to the top hash or Merkle root. The merkle root hash is contained within the block, along with the hash of the previous block header, the current block’s header, and the nonce.

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