Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#1849
  1. To make it almost impossible to change anything in previous blocks.
  2. Previous hash, transactions and nonce
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#1850
  1. To keep the network secure. nonce
  2. nonce, data, previous hash, current hash.
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#1851
  1. To keep the trustless data uncoruptable.
  2. Previous Hash, tranactions & Nounce on all current blocks.
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#1852

Homework on Blockchain and Mining Visually - Questions

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

The blocks are linked in such a way as, one thing changes - everything changes. Data immutability.

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

The blockchain structure is a chain of data blocks. Each block contains: block header (block version number; hash of previous block; hash of merkle root; time, target for difficulty and nonce), in the body of the block are the transactions.

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#1853

  1. Why is it important that the blocks are cryptographically linked together?
    For network security. This link makes it very difficult to make any changes to a particular block. If you make a change to one block, all blocks in the chain must be mined again to get new hashes.

  2. What does the block structure look like in bitcoin?
    Time stamp
    Block number
    Difficulty target
    Transactions
    Nonce
    Block size
    Previous block hash
    Current block hash
    …and more.

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#1854
  1. So it would be almost impossible to alter any of the blocks.
  2. All blocks contain:
  • Block number.
  • Nonce
  • Transactions data.
  • Hash from the previous block - the origin block is an exception.
  • Current hash
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#1855
  1. To make it really difficult, time consuming and ultimately a waste of time and money (in wasted electricity costs) to change anything in the previously mined blocks
  2. You have a) previous hash, b) Transaction List and c) Nonce - random number for miners to find.
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#1856

  1. If data is changed in one of the previous blocks, the link between that block and the blocks after that will be broken. Because 1 single change will alter the whole hash.

  2. A block has a block header (version, time, bits, nonce, prev block hash, merkle root hash), list of tx’s.

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#1857

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

This is the fundamental of Blockchain It ensures transparency and integrity between the blocks. It is very very difficult to change or interfere with blocks that have been linked mathematically.

2 What does the block structure look like in bitcoin?

It contains Version, Previous Block Hash, Root hash, Timestamp, Target, Nonce, Block Header, and Size and Transactions.

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#1858

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

To keep links from being broken. The become unbroken. It can’t never be altered.

What does the block structure look like in bitcoin?

A block is a container data structure . In the Bitcoin world, a block contains more than 500 transactions on average. The average size of a block seems to be 1MB (source).

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#1859

  1. Makes difficult to hack into and make changes, provides security, and immutability

  2. Nonce, Data (TX), Previous Hash, Current hash (output)

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#1860

Homework on Blockchain and Mining Visually - Questions

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

it makes the blocks worthless and so costy for the miners to go back and remin the blocks even if its possible practically.

also i makes the blockchain impossible to be hacked and manipulated.

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

its a block that contains a hash(like a fingerprint)that this hash contains the previous hash of the previous block which is including transactions information (UTXO)and Nonce and so on.
:grinning:

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#1861
  1. secure the blockchain against manipulation
  2. tx hashes in the block, prev. hash and the nonce to be guessed
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#1862

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Answers

  1. Security.
  2. Hash of previous block, current block, list of txs, nonce.
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#1863

  1. It’s “almost” impossible to change something in excisting block. Data is immutable. Linking keeps blockchain more safe either.

  2. HASH= previous hash+ tx list +nonce

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#1864

  1. To keep the integrity of the blockchain. The network will always go first to the longest chain because it is the one that has the most Proof of Work.

  2. It is made by the Previous Block hash, the List of Transactions in the current block, the nonce and the current block hash.

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#1865
  • Why is it important that the blocks are cryptographically linked together?
    –They are cryptographically linked together because this ensures that the network stays secure and honest. The cryptographic puzzle requires miners to spend a lot of electricity to get their block appended to the blockchain (incentive), so the cryptographic link helps keep the trust in math and physics, and not by a central authority.
  • What does the block structure look like in bitcoin?
    –The hash of the current block contains the hash of that block, the transactions in the block, the hash of the previous block and the nonce that needs to be guessed.
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#1866

  1. Its important because the link shows the order of transactions, transactions can be verified because the links comtain the previous hash.

  2. A block is structured with the hash from the previous block with a lost of transactions and a new hash based on the prevois hash, timestamp, and transactions within the block.

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#1867
  1. For blockchain security and to have a consistent unalterable record of transactions.
    2.Previous hash, nonce, current hash, block number/header,
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#1868

  1. Ensures data is difficult to change and data is immutable

  2. Hash of previous block > tx > nonce = hash for new block

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