Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#2975
  1. Why is it important that the blocks are cryptographically linked together?
  • It is important that the blocks are cryptographically linked together to ensure that they remain inmutable therefore confirming no double spends and ensuring integrity of data.
  1. What does the block structure look like in bitcoin?
  • Each block in the blockchain contains important information forming its´ structure including: transactions in that block, previous hash, block size and nonce.
1 Like
#2976

  1. Why is it important that the blocks are cryptographically linked together?
    -To prevent alteration of previous blocks

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

  • A block contains a prev hash, tx list & nonce
1 Like
#2977

  1. So it is not possible to change any past block without recreating all new blocks created after thus making the network very secure and transparent

  2. A block consist of the hash of the previous block, a list of Txs and a nounce

1 Like
#2978

  1. It’s important because it helps improve security and makes the network a trust-less one.

  2. Each block is made up of transactions’ data, nonces, and a hash from the previous block.

1 Like
#2979

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together
    Blocks being linked cryptographically together ensures that no one can change any data on any part of the blockchain. any changes will result in the links being destroyed and destroying that block essentially making these attempts useless and futile if one is trying to steal or double spend.

  2. What does the block structure look like in bitcoin?
    Block structure looks like this: block #/header, nonce, data(transaction), previous hash, and current hash. each block is linked to another block and the nonces essentially get mined to hash each block below the target number.

2 Likes
#2980

  1. Each block has a connection to the previous block so therefore if a block is tampered with every block after it will show there has been a change.

  2. Previous block hash, current block transaction list, and nonce.

1 Like
#2981
  1. Why is it important that the blocks are cryptographically linked together? To secure the network and ensure its integrity. It ensures that the data in a block cannot be tampered with; as all blocks are linked with the previous block to form a blockchain. If someone tries to modify data in any way, then all subsequent links break.
  2. What does the block structure look like in bitcoin? It’s a Hash function puzzle. BTC uses the sha256 function (data) = hash ( Tx or data list ) + hash ( previous block hash ) + random number “ nonce ” must be less than Target. Miners must find nonce(repetitively guesting and hashing) until the nonce equals the Target. The Block has: the previous block hash, current Block Tx (data) and the nonce must be found for the block.
2 Likes
#2982

  1. It ensure the security and integrity of the blockchain, preventing alteration, double spending, and other forms of manipulation.

  2. Each block consists of a) the previous block’s hash, b) the current block’s transactions, and c) a nonce (random number).

2 Likes
#2983

  1. Answer: Because that is what makes a blockchain immutable, or almost impossible to corrupt. To change a block in a blockchain you have to change all blocks and create new hashed relations between the blocks. This becomes proportionally harder the larger the blockchain becomes.

  2. Answer: Each block has a) Transaction data that is hashed and organised as a merkle tree (thank you @jon_m) b) The hash of the previous block which creates the cryptographic link c) A nonce d) A difficulty target e) A block’s number in the form of a hash value f) Time stamp

3 Likes
#2984

1, because it provides security and makes it very difficult, ( if not impossible ) to alter it, each block are linked to the previous one and any change made would break this link.

2, it contains data added to the block( transactions) previous hash and a nonce to be guessed.

2 Likes
#2985

Why is it important that the blocks are cryptographically linked together?
So if there is a change to a previous block, all blocks that follow will no longer be linked together and must be re-mined.

What does the block structure look like in bitcoin?
Each block/new hash contains the old hash, the transaction list and the number that is less than the target number, called a NONCE.

2 Likes
#2986

  1. Verification is made possible by cryptographically linking the blocks together.

  2. The first transaction is always the miner reward. Subsequent blocks are a hash generated from the previous hash, transaction list, and the nonce.

2 Likes
#2987

1 More are the connections more is difficult to change blocks. To create new hashes, should be changed more blocks connected in relations, and this, at the actually state of the technology, is impossible.
2 Just like a puzzle? The previous hash plus all the hash list transactions, plus a Nonce, a random number to guess = current hash block.

2 Likes
#2988

  1. It makes it impossible to edit the blocks behind the current one. Immutability.

  2. The block has a list of transactions, the previous block’s hash, a nonce and its own hash calculated by hashing all three together(list of TX, prev hash, nonce).

2 Likes
#2989
  1. a block hash is generated based precisely on the contents of the block. so, if the slightest hint of the vaguest whiff of a change is made to the block contents after the fact, then the block hash changes immediately…since the link is based on the block hashes, any change to any of the hashes in a link will cause that link to break …this will stand out like a sore thumb which is exactly what you want when building data that needs to be immutable…where you can’t erase or rewrite history so to speak.
  2. blocks consist of the previous block hash, nonce, transactions, and a hash block header based on the prior header, nonce, and transactions
2 Likes
#2990
  1. Why is it important that the blocks are cryptographically linked together? This determines the integrity of the block chain to secure the network, ensure consensus and no double spending. Incentive built in for for following the rules.
  2. What does the block structure look like in bitcoin? Links a list of numbers with hash of previous block and block listed (UXTO to current block) plus the nonce (random number) which mist be lower.
2 Likes
#2991

  1. It is important that blocks are linked together to ensure there is no altering of blocks once they are produced. This will not allow for someone to go back and alter a block as it will break the chain.

  2. The block is structured with the transaction data, the previous block’s hash, and a nonce which is to be guessed. This all comes together to create a hash that is lower than the target hash that is needed to create a block.

2 Likes
#2992
  1. By linking the blocks together you make them immutable. It makes it highly improbable that you can change one piece of data, without invalidating all the blocks after that block.
  2. Previous block/hash, transaction(s) data, magic number, difficulty goal/target number.
2 Likes
#2993

  1. To prevent data tampering/manipulation and ensure the integrity of the data.

  2. The Nonce, Data(Tx), and previous hash to determine the current hash.

2 Likes
#2994
  1. So that it is more secure and difficult to go back and alter.
  2. Hash at header of new block with a nonce, list of transactions within the block and the previous block’s hash.
2 Likes