Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4058

The importance of the coupling of the blocks cryptographically is that if any change is conducted by anyone the Hash will change completely and all the succeeding Blocks will have to be redone. The BTC block Structure is as follows:
1.- Block size (4 bytes)
2.- Block Header (80 bytes)
3.- TX Counter (1-9 bytes)
4.- Variable (TX)

In number 2, will be sub-divided just like:
2.1.- Version - Tracks Software/Protocol Upgrades
2.2.- Previous Block Hash
2.3.- Merkle Root - The way the Hash of the Tx that are joined up
2.4.- Timestamps - Time elapsed since Unix Epoch in Seconds
2.5.- Difficulty Target - PoW Algorithm of the Difficulty Target
2.6.- Nonce - A counter used for the Difficulty Target

I used the link provided by @alko89 to help my Research.

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#4059

  1. Why is it important that the blocks are cryptographically linked together?
    -Because it insures that blocks remain unchanged, data immutability.

  2. What does the block structure look like in bitcoin?
    -There are the transactions, the blocks, hashes of previous blocks, and the nonce that needs to be guessed.

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#4060

1. Why is it important that the blocks are cryptographically linked together?
Its important for the blocks to be cryptographically to add more security to the network and increase the difficulty (while at the same time decreasing incentive) for an attacker to change a transaction or multiple transactions in a block.

Because the blocks are cryptographically linked together (the hash of a block is based on the transactions in that block, plus the nonce guessed by the mining node computer, plus the hash of the previous block) if an attacker was to change a transaction in a given block its hash would change and so would the hashes of all the blocks proceeding it, requiring the attacker to not only re-mine these cryptographic links but do this fast enough so that they can continuously mine the new blocks of transactions being propagated through the network. This would essentially mean that the malicious actor would waste so much money spent on electricity used for the computing power that it would most probably be better to play by the rules.

2. What does the block structure look like in bitcoin?
The block in the bitcoin blockchain consists of transactions, the hash of the previous block, and a nonce or number guessed by the miner to ensure the hash generated is below a certain target value set by the network.

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#4061

The blocks are cryptographically linked in order to maintain the security of the blockchain. There can be no changing of transactions or double spending without breaking the chain

  1. The block is made up of the hash created by the transactions within the block plus the hash from the previous block plus the nonce that must be guessed by the miner
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#4062

  1. It secures the network from manipulation

  2. A block consists of a list of current transactions that the miner has just picked up, the hash of the previous block and a nonce.

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#4063

It ensures that the blockchain is immutable as previous blocks would need to be mined with 51%+ hashpower to be able to have benefit in mining previous hashes.

It looks like a nonce, tx list and previous hash + new hash. The blocksize may differ. There is a target and the nonce needs to be lower for the miner to have his tx included.

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#4064

  1. Why is it important that the blocks are cryptographically linked together? The cryptographic links bridge past transactions to future transactions as this data is used in the cyptographic puzzle miners must solve to append a block. This creates security as trying to alter a past block would be virtually impossible, thereby creating a consensus ledger/one version of the truth.

  2. What does the block structure look like in bitcoin? The structure contains the hash from the previous block, current transactions, and the nonce.

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#4065
  1. Why is it important that the blocks are cryptographically linked together? Because when the transactions are changed in anyone block it affects the hash which in turn affects all the hashs of the future blocks.
    What does the block structure look like in bitcoin? Its made up of the blocks hash, transactions in the block, nonce and the previous blocks hash.
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#4066

  1. it’s important that the blocks are linked for security: essentially no one can falsify the history, and it provides a proof of what has happened before it in such a way that only credible transactions are included and those included are indelible (also immutable).

  2. the block structure looks like the prev hash + current data (unconfirmed transactions list) + nonce (“number only used once” to be recursive about it!) all to be hashed (apparently there’s more to it, according to @marsrvr: + transaction counter + blocksize and block header combines prev hash + current target, apparently.

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#4067

  1. It is important that the blocks are cryptographically linked together as to create “A Digital Stone” that cannot be altered, securing the Honesty ; Trustlessness ; Integrity of the Network.

  2. Block Structure = Previous Transaction / First Transaction - (00000000000) (+) UTXO / Data - (a+b) (+) Nonce # - Random # (=) Unique Hash / Digital Fingerprint.

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#4068

1. Why is it important that the blocks are cryptographically linked together?
It makes the blockchain that much more secure and resistant to fraud. If all blocks reference and are linked to the previous block in the chain then any change would alter the entire blockchain and it would be rejected by the nodes and miners.

2. What does the block structure look like in bitcoin?
Each block has: nonce, tx/data, prev hash, current hash

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#4069

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
  • So that there will be a link between each block that proves the previous blocks were not tampered with.
  1. What does the block structure look like in bitcoin?
    image
    (righto.com)
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#4070
  1. It is important that the blocks are cryptographically linked together because all of the hash functions are based off of the previous hashed blocks, which creates that special fingerprint of that block. By creating that link of all of the previous blocks, it creates validity and secures the network.
  2. The block structure is made up of a hash function that is equal to the previous hash of that block, the transaction list and the nonce (a generated random number).
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#4071
  1. Because blocks are cryptographically linked together it makes it very difficult for previous transactions to be edited and changed, as it will break the link between all other blocks the one being changed is connected to.
  2. The block structure contains the previous hash, transaction list, and the nonce.
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#4072
  1. Why is it important that the blocks are cryptographically linked together?
    To keep a traceable order, and to build unique links in this chained process.
  2. What does the block structure look like in bitcoin?
    The structure consists of a header and a transaction list(s)
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#4073

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    To ensure the integrity of the blockchain. SHA 256 is used on each block and each current block contains the hash of the previous block any changes will deem the block invalid until re-minded and corrected.
  2. What does the block structure look like in bitcoin
    Block number > Nonce > Transaction Data > Hash of the Previous Block > Hash of current block
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#4074
  1. because each new block consists of all the information from the previous blocks in order to secure the network
  2. each block consists of the nonce, transactions, previous block hash and each new block has to include all the previous data
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#4075

  1. It is important that blocks are cryptographically linked together to assure security and transparency. If links could be altered the system would not be “trustless”.

  2. Block structure in bitcoin is based on the previous hash, tx list and nonce that needs to be guessed.

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#4076

  1. This creates security and integrity of the network. This decentivizes anyone from going back to previous blocks and changing anything. Doing so, would break all the links and everything would need to be re-mined. This would cost a fortune in time and money.

  2. Each block’s hash is calculated from the previous block’s hash + the current block’s transaction list + a nonce (which is guessed by miners)

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#4077
  1. Because that is the only way it works correctly. Its very important because we trust the math and if they change one thing , everything else changes and you will get rejected by the other nodes and have to start all over.
  2. each block has a hash , and each blocked is based on previous transaction from the last block and a nonce.
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