Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4221
  1. It ensures the integrity of the system, as changes in the past would cause all the data from that point to be changed as well (which is practically speaking impossible).
  2. Blocks consist of the tx data, hash of the previous and current block, nonce, time and transaction data (amount transferred, fees, reward…).
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#4222

  1. When they are cryptographically linked they become practically immutable.

  2. Each block will contain the hash of the previous block, all transaction data of the current block, and a nonce.

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#4223

For Security and integrity of the blockchain

((hash of the previous block) + (Tx of current block) + (Nonce)) = Hash < Target

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#4224
  1. Why is it important that the blocks are cryptographically linked together?

As 1 block builds on top of another. The links secure this structure ensuring integrity of the blockchain.

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

Hash plus Hash from previous block
TX
Nonce

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#4225
  1. Why is it important that the blocks are cryptographically linked together?
    When mining a new block one part of the data used in the hashing algorithm is the hash of the previous block. This is the link between the new block and previous block. If one of the old blocks is altered the link between all new blocks will be broken meaning the miner has to catch up hashing all new blocks after the altered one and have the longest chain on order to successfully alter the block chain
  2. What does the block structure look like in bitcoin?
    Each block has a hash which is created by miners when hashing data (previous hash, transaction list, nonce). This hash is the link between all the blocks. The blocks are connected together via this link (previous hashes) forming the blockchain
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#4226

Answer 1 - To ensure that tempering the any blocks is very very difficult and shall require remining of each previous block from the tempered block as all are linked with hash of previous block

Answer 2 -

Previous Hash
Nonce
Transactions List
Present Block Hash

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#4227
  1. Why is it important that the blocks are cryptographically linked together?
    So that altering blocks is interdependent and makes that faulty block so much harder to get back to the original chain. Because there is only one truth in bitcoin and that is the longest chain.
  2. What does the block structure look like in bitcoin?
    It consists of transaction list, previous hash and nonce and hash of the block.
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#4228
  1. Why is it important that the blocks are cryptographically linked together?
    Because then you are unable to modify blocks without disrupting all following blocks.
  2. What does the block structure look like in bitcoin?
    It consists of transactions, previous hash, nonce and the calculated current block hash.
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#4229

1- Linking blocks together keeps the records secure and varified. If someone tried to change any data in a block they woukld have to mine all following blocks and do this faster than the main chain if they wanted there transaction to be legitamised.
2- block of data (Hash from last block, UTXO’s, Block hash) - link - block of data. The link is the Nonce from the first block, from which the hash of the second block is generated.

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#4230

Homework on Blockchain and Mining Visually - Questions

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

This way, if someone tries to modify a previous block, all following blocks will fail, meaning he will need to mine all the blocks again by himself, which is impossible.

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

Previous Hash
Nonce
Tx List
Current Block Hash

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#4231

  1. This way the latest block contains all previous blocks.

  2. Each block contains the hash of the block that preceded it, information of all transactions associated with it, its nonce, and its hash.

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#4232

  1. To secure the blockchain. If you change one little detail in a already mined block the whole rest of the chain would colapse. Only the longest chain is exapted.

  2. Tx. previous hash. nounce

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#4233
  1. This ensures that if a historic block gets altered it will be detected and not accepted because all subsequent hashes will not match anymore. In essence this is what makes the blockchain secure and its data tamper-proof.
  2. A block basically consists of a block identifier, the previous block hash, the transactions data and the current block hash
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#4234

1. Why is it important that the blocks are cryptographically linked together?
To incentivise miners to play by the rules by making it very difficult for someone to try and corrupt the system.

2. What does the block structure look like in bitcoin?
Hash
Previous Hash
Nonce
Tx list

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#4235

Hello!

  1. It is important that the blocks are cryptographically linked together because it makes sure that they rely on each other resulting in Proof of Work.
  2. The block structure in bitcoin has a) previous hash from previous block b) transactions list c) nonce guessed by computer and d) the hash for that block resulting from all inputs.
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#4236
  1. Its important that blocks are cryptographically linked together because the blocks carry information from previous blocks. This process combined with prrof of work ensure the security of the blockchain.
  2. The block structure looks like a chain, each block of the chain is made up of its own hash, the previous blocks hash, the transaction list, and a nonce.
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#4237

1. Why is it important that the blocks are cryptographically linked together?
This makes it infeasible to impossible to change data on previous blocks because doing so would then invalidate all blocks after the changed block; if that were to happen, the person changing the block would then have to re-mine all subsequent blocks faster then all the other miners on the network that are mining new blocks.

2. What does the block structure look like in bitcoin?
I suppose it would look something like an enormously long train, where multiple companies would be competing for who gets to attach their own car to the front of the train.
I misunderstood the question, haha. The individual block structure in Bitcoin is a hash of:
• previous blocks hash signature
• a list of transactions
• the nonce

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#4238

  1. by linking the blocks together, they are temper-proof. that keeps the integrity intact so no one could double spend or reverse a transaction.

  2. every block hash is based on the hash of the previous block, the transaction in the block and the nonce.

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#4239

  1. Why is it important that the blocks are cryptographically linked together?
    These links are special because they are based upon the previous Block’s Hash, which is why the Blockchain is very secure.
    If you change something in an earlier Block, all the links from that Block going forward will be broken. All NODES will see that this Blockchain is invalidated because it doesn’t make sense.
    Going back in time to revise earlier Blocks becomes exponentially more difficult.

  2. What does the block structure look like in bitcoin?
    The block structure in Bitcoin is a hash of: (1)Previous blocks Hash (2)All transactions in Current Block (3)A random number called “NONCE”.

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#4240
  1. Why is it important that the blocks are cryptographically linked together?
  • Each block is linked to its previous block to include the blockchain history in the calculation of the hash of the current block. In that way, changing of historical information is made impossible.
  1. What does the block structure look like in bitcoin?
  • A block contains the transactions wich should be added to the blockchain plus the hash of the previous block. In addition, a random number called nonce is included.
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