Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#42

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    -Then it is really hard to change a block.
  2. What does the block structure look like in bitcoin?
    Hash based on Txs
    previous hash
    Nonce
#43

  1. It is important the blocks are crypto linked because it supports security. Having them linked makes altering a block in the past extremely difficult.

  2. The block structure in bitcoin is a temporal chain of connected information, with each block containing the previous hash, transactions, and nonce hashed together.

#44
  1. Because it prevents any alterations to inside the live chain. If one block is altered, the hashes of all the blocks that were mined before the malicious block will be altered too ( the hashes thereof ). This way miners and nodes will smell the bullshit and reject the malicious block.

2 A block contains transactions, a hash of the previous block and time stamps.

#45

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together? It makes the entire system trustworthy through math and physics. Cryptography makes it difficult or next to impossible to be changed. Everything is linked together. It’s like a puzzle that are all connected together. It also eliminates double spending.
  2. What does the block structure look like in bitcoin? It looks like many blocks linked together. Data in Shaw 256 into a unique fingerprint. Each block has a hash or a unique fingerprint based on all the transactions of current block and the previous block.
1 Like
#46
  1. To secure the network and make the matematical pussle for the next block.
  2. It is based on three things: The hashnumber from previous block (Sorry my bad spelling in english), the transaction in the new block and the nonce number.
#47

  1. Blocks cryptographically linked makes the network safer preventing changes on the blocks. Any changes on any block would be rapidly be noticed by other blocks ensuring immutability and finality.

  2. A block is compound by:

  • Current Block Hash
  • Previous Block Hash
  • Transactions
  • Nonce
#48

Because if you try to change one block it changes all blocks in the chain.

block number
nonce
tx
previous hash
new hash

#49
  1. to ensure that historical transactions are not tempered with.
  2. HASH, NONCE, Prev.block HASH, Tx List.
#50

Homework on Stale Blocks.

  1. What happens in the bitcoin network when two miners solve a block at the same time? Both blocks would be valid; however, sooner or later the blockchain with the longest blockchain and with the most difficult Proof of Work will be the truth that will prevail.
  2. What is a stale block? Blocks that were in the blockchain at one time but were dropped because of a competing blockchain. Dropped blocks are called stale blocks or orphaned blocks.
  3. How do stale blocks occur? When blocks are coming out at a faster rate and begin to compete with each other. The longest blockchain prevails. The blockchain with the most proof of work and the difficulty of the blocks would prevail. The blocks that are no longer use become stale.
  4. Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction? To prevent your block from being dropped and to maintain the efficiency of the blockchain. The best practice is to wait for 6 confirmations to come after your block to be confirmed.
#51

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

  2. The link between the previous block and the next is a cryptographical puzzle.

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

  4. The hash of the block is based on the tx in the block and the previous hash + the nonce that needs to be guessed

#52

Why is it important that the blocks are cryptographically linked together?
Because this makes changing any confirmed data difficult and ensures the immutability of the blockchain.

What does the block structure look like in bitcoin?
A Bitcoin block consists of the block number, hash of the previous block, transaction data for the current block, the nonce, and the resulting hash (unique fingerprint) for the block.

1 Like
#53
  1. Because if you change anything in the block- hash will change and blocks will not be linked anymore
  2. previous block hash, transactions and nonce
#54
  1. It is important to main the integrity of the Blockchain and to prevent any foul play by any. They are so linked because each subsequent new block must open with the hash function output of the previous block as input.
  2. A block is a container data structure and in bitcoin it can contain more than 500 transactions but not more than 1MB in size
#55

  1. The blocks need to be hash linked because any bad actor will no only need to alter the existing block but the ones previously, the time effort to do this will mean the main blockchain has moved on, longest blockchain becomes valid

  2. The block structure is made up of the three element
    The previous hash block, the transaction list and the nonce
    This is used to create the block hash which needs to be below target value of the difficulty adjustment to become the new successful block

#56

  1. Why is it important that the blocks are cryptographically linked together?
    To ensure the integrity of the blockchain. The cryptographically generated hash used during the addition of each block prevents the data of previous blocks from being changed as such a change would have a cascading effect which would invalidate all subsequent blocks.

  2. What does the block structure look like in bitcoin?
    Each block is comprised:
    a. Hash of the previous block
    b. List of transactions
    c. The nonce

#57

  1. It keeps the integrity of the ledger, it’s the secret sauce

  2. Hashes, ins and outs, data, nonce

#58
  1. Because it ensures previous transactions stay untacked.
  2. Previous has plus transactions plus nonce.
#59

1. Why is it important that the blocks are cryptographically linked together?
It is important for the security and integrity of the network. A transaction in a block cannot be modified without breaking its link to the subsequent block.

2. What does the block structure look like in bitcoin?
It contains the hash of the previous block, the transactions as well a random number miners have to guess, the nonce.

#60
  1. It’s how the security of the network is maintained. Linked blocks cannot be changed without breaking the chain.
  2. Hash of the prior block, plus transactions plus a nonce.
#61
  1. The importance for the blocks to be cryptographically linked is for the integrity of the blockchain. Bitcoin blockchain is meant to be immutable and decentralised. Nobody is supposed to be able to change any data once its mined.

2} Each block has a block Header which consists among others like timestamp, a cryptographic hash of the previous block ensuring the linkage to all other blocks in the chain. It also has a nonce number which the miners randomly guess so that after hashing everything in the block, must be either equal to or lower than the Target number. Lastly the Merkle root of all transactions from that block, averaging slightly more than 500 transactions per block (1 MB in size.)