Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#3436

  1. So the hash can continue or to prevent data from being changed.

  2. Block - Nonce - Data - Previous Hash - Hash

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#3437

The question is “the Block Structure” not “the blockchain structure” your answer is for the structure of the chain.

#3438

  1. They are cryptographically linked by including the hash of the previous block into the hash of the current block. This means that it is (almost) impossible, and extremely costly, to change any of the blocks in the blockchain.

  2. A block contains transaction data, a nonce, and a hash which is a cryptogram of the transaction data, the nonce, and the hash of the previous block.

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#3439

Hi Maki, would you be able to explain the difference? Thanks!

#3440
  1. Why is it important that the blocks are cryptographically linked together? It creates immutability in the blockchain network, meaning that transactions in previous blocks cannot be altered.
  2. What does the block structure look like in bitcoin? Block header (Hash from previous block, Metadata, Nonce, Merkel root) & Transactions
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#3441

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    By cryptographically linking the blocks, it secures the network and limits interference. If a link is broken, all that follow will be discarded too.

  2. What does the block structure look like in bitcoin?
    Each block consists of:
    Transactions + Previous block’s hash + nonce -> are combined and hashed in order to guess the Target number ( low or high difficulty based on the number of miners on the network)

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#3442

  1. Why is it important that the blocks are cryptographically linked together?
    the cryptographic link includes the components that verify the integrity of the previous blocks by including the hash of the previous, the TX list and the nonce and makes a new fingerprint that reflects the information contained previously in the blockchain

  2. What does the block structure look like in bitcoin?
    From: https://en.bitcoin.it/wiki/Block
    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 the nonce, an answer to a difficult-to-solve mathematical puzzle - the answer to which is unique to each block.

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#3443
  1. Why is it important that the blocks are cryptographically linked together?
    it increases security by making it impossible to modify a previously existing block without going back and modifying all previous blocks
  2. What does the block structure look like in bitcoin?
    data header and a detail component header contains the hash of the previous block and the hash of the current block and the detail area contains the transaction hash
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#3444

Why is it important that the blocks are cryptographically linked together?
1.It secures the network you cannot alter history or it will break the entire chain.

What does the block structure look like in bitcoin?
2. Previous Hash
Transactions List
Nonce

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#3445
  1. Why is it important that the blocks are cryptographically linked together?
    It secures the network, transactions can’t be altered. It’s almost impossible and very costly to change blocks.
  2. What does the block structure look like in bitcoin?
    A block contains Transactions, previous hash, current hash, and the nounce.
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#3446
  1. b/c going back attempting to change a block changes all other blocks previous. Keeps everything secure & visible to the public.
  2. the block is made up of tx data, the previous hash output & nounce which creates the lowest hash output for a new block.
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#3447

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

  • It renders it impractical for a miner to go back and fiddle with the data.
  • Answered in my pervious post.

What does the block structure look like in bitcoin?
Bitcoin Wiki
image

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#3448

  1. To secure the network

  2. Current hash - previous hash - transaction list - nonce

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#3449

  1. Having the blocks cryptographically linked means that if information changes in one of them it will change all of the blocks in the chain. This ensures that the integrity and validity of the blockchain is retained.

  2. You have a hash from the previous block, plus the transactions/information in the current block, plus a nonce (a special number that needs to be below a target specified by the network, based on how many miners there are trying to mine that block). Each block is linked to the previous block by the previous hash.

2 Likes
#3450

Why is it important that the blocks are cryptographically linked together?
Blocks need to be cryptographically linked together to ensure the security of the network, this works because if any of the data in a previously mined block is changed it will change the hash of all other blocks in front of it, these blocks would need to be rehashed again to keep the chain going but due to the hashrate available this would not be possible.

What does the block structure look like in bitcoin?
Blocks contain the previous blocks hash, TXN data and the nonce which all together makes the hash of the block.

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#3451

Blockchain structure is a back-linked list of blocks of transactions. A block structure consists of a block header and a block body. The block body contains transactions and Each block has a unique hash code that allows others to distinguish it from other blocks.

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#3452

  1. The blocks are cryptographically linked together to ensure security, integrity, and authenticity.

  2. Bitcoin block structure contains - the previous block’s hash, a header, and a list of transactions.

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#3453

  1. Why is it important that the blocks are cryptographically linked together?
    Each block contains a hash of a previous block. This is important from the security point of view. To change 1 block you have to change all next blocks which is impossible. It is a security that makes it important.

  2. What does the block structure look like in bitcoin?
    The block structure looks like a chain. The blocks follow each other in the form of a chain. Every block consists of a checke tx list, nonce, previous hash.

2 Likes
#3454

  1. It’s important that the blocks are cryptographically linked together because if someone wants to go in and change a previous block it will disrupt the connection between that block and all following blocks, meaning that it would be extremely difficult (or impossible) to actually change a transaction that took place because then you would have to go in and re-hash every following block.

  2. Each block contains all previous blocks, the nonce, transactions, and the previous hash, and all of this information is what is contained in the newly generated hash for that block.

1 Like
#3455
  1. Why is it important that the blocks are cryptographically linked together?

To preserve data integrity and security, since changing the data, nonce, or hash of a previous block would change the hash of all block after it and thus invalidate these blocks and require them to be remined, and remaining would not be possible due to the longest chain being however many blocks ahead of the invalidated chain

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

The block structure of a block contains the previous block’s hash, the nonce which is the value guess by the miner who won the block, the block’s transaction data, and the block’s resulting hash calculated from the proceeding three values

1 Like