Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4241

  1. It is important that the blocks are cryptographically linked together to create a strong and secure blockchain, retaining integrity of the information stored on the blockchain and making it impossible to change any one part without changing the whole

  2. Biitcoin block structure:

Header:
version (describes structure of data inside the block so computers can read)
block size (bytes)
previous block hash
merkle Root Hash (hash for transactions of this block)
timestamp
bits (difficulty target)
nonce

Transactions

2 Likes
#4242
  1. The blocks are cryptographically linked such that immutability is insuredā€¦ by linking said blocks there is a disincentive to go back to an older block and make a change as would cause all subsequent blocks in the chain (both existing and those not yet added) would need to be re-minedā€¦ a prohibitive and daunting exercise, thus for all intents and purposes miners are always working prospectively and would never contemplate a retroactive change in the chain.
  2. The blocks in a block chain stack onto each other in chronological orderā€¦ ie an approved/verified block is added to the block that preceded it in sequence and thus stacking the blockchain into an incrementally longer chain.

Each new block to be added to the blockchain must honor the hash of the previous block and to that it adds the transactions in its own block to create a new hash unique to it. This unique block, once accepted, than forms part of the evergreen blockchain.

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#4243

1.) It makes the blockchain censorship resitant, when you only change a little bit in the block, everything is different because of sha 256.

2.) The block structure isā€¦ Previous hash- Transactions- Nonce

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#4244
  1. Why is it important that the blocks are cryptographically linked together?

These cryptographic links make the blockchain immutable, which secures the network.

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

A block has a hash, a list of transactions, and a nonce. This information is partly derived from the previous block in the chain.

2 Likes
#4245
  1. to make it practically impossible to change previous data
  2. Every block contains the hash of the previous block, list of transactions, hash of current block, nonce
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#4246
  1. Why is it important that the blocks are cryptographically linked together?
    This ensures the security of the network by making the puzzles more and more difficult as time goes on (more blocks creates), ensures the chain does not have disruption from ā€œbad actorsā€
  2. What does the block structure look like in bitcoin?
    Hash of current block = (lower than target number)
    Prev Hash +
    TX list +
    nonce
2 Likes
#4247

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    Answer. To ensure that someone does not maliciously modify a prior block. Hashes are taken from prior blocks/hashes to build/link them all together.
  1. What does the block structure look like in bitcoin?
    Answer. Link Lists. One block is connected to another in a sequential manner.
2 Likes
#4248

  1. This makes it more difficult to change a block. When you change one block, you have to change all the blocks and create new hashed relations between the blocks, something which is impossible.

    1. Block number > Nonce > Transaction Data > Hash of the Previous Block > Hash of current block
2 Likes
#4249

  1. so nobody can adjust previous blocks.

  2. It consist of the previous hash, a list of transaction and the correct nonce.

2 Likes
#4250

  1. it helps to ensure the stability of the network because no ones is able to go back and change any transaction in the previous blocks.

  2. the block structure in bitcoin looks like a double-locked keychain with only a one-way forward direction as it extents.

2 Likes
#4251

  1. It is important that blocks are cryptographically linked toghether so that no one can go back and change the data of previous blocks. As they share a relationship with the current block, any changes would break the entire chain after the modification.

  2. Hash - Block size - version - previous hash - merkel root - timestamp - difficulty - nonce - transaction counter - transactions list

2 Likes
#4252
  1. For the security of the whole chain
  2. By the hash generated with the I/O
2 Likes
#4253
  1. shows higher pow and thus increases security of the network
  2. block, link, block, link, block, and grows like that. the blocks hash include hash of the previous block.
3 Likes
#4254 
1.  This ensures that the blocks remain immutable.
    
2. Block structure e in bitcoin:
   Nuance, block size, block header, hash of previous block, current target, transactions, transaction counter.
2 Likes
#4255
  1. Why is it important that the blocks are cryptographically linked together?
    So that if someone tries to change a past block, they need to change all future ones too, making the effort of being a bad actor not make sense economically.
  2. What does the block structure look like in bitcoin?
    Nonce+New TXs+previous blockā€™s hash
2 Likes
#4256

  1. Why is it important that the blocks are cryptographically linked together?
    Because this makes the network secure and every block dependent on each other in a way that previously mined blocks cannot be altered cause they will instantly invalidate the new blocks already mined. This feature makes the network resistant to attacks trying to modify the truth already mined.

  2. What does the block structure look like in bitcoin?
    It is made of a thatā€™s composed of a header and a Body:

Header:
ā€¢ which contains the hash of the previous block.
ā€¢ Timestamp
ā€¢ Nonce
ā€¢ And the Merkle root (Root hash of a Merkle three)

Body, which has all the transaction data

1 Like
#4258
  • Why is it important that the blocks are cryptographically linked together?

Because that`s what build the strong bond between blocks.

  • What does the block structure look like in bitcoin?

inputs -> hash (tx`s, previous hash, nonce) ->outputs

1 Like
#4259

  1. It is important that all blocks are cryptographically linked together so that if one character or digit is changed in a previous block then all following blocks are also changed. This keeps the blockchain secure.

  2. The block structure in bitcoin contains the previous hash, transactions list, and a nonce

1 Like
#4260

  1. To make any changes or cheating process practically impossible

  2. Block structure consists of:
    Itā€™s own Hash, which is build from
    a nonce
    the previous hash
    and the transactions

1 Like
#4261

  1. Why is it important that the blocks are cryptographically linked together?
    -to setup blockchain integrity, no double spending, no censorship, and a secure network.

  2. What does the block structure look like in bitcoin?
    -previous hash
    -tx
    -nonce

1 Like