Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4160
  1. to maintain immutable characteristics within the blockchain.
  2. prev block hash - transaction - nounce (compute a hash within the threshold to keep difficulty) - blocksize - header - current target -
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#4161

  1. The connection between the block is part of the encryption the hash and therefor the blocks itself, if anybody tries to change any aspect of the blockchain in the past, everything that builds up on it “falls apart” if you want. Every block uses the previous hash to calculate the new hash if anything is changed the system won’t verify blocks, transactions, UTXOs.
    It is one of the main pillars of security in the system.

  2. Block structure in Bitcoin consists of: The previous hash, the transactions the miner choses (transactions do not have to be a part of a block but since it makes money miners will include them, the first block has no transactions in it), the block reward and the transaction fees are in the block as difference between input and output, timestamp, merkle root, size, weight, hight, difficulty, version.

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#4162
  1. It ensures that the data is unable to be altered without being noticed and can’t be tampered with.
  2. Blockchain looks like a double linked data structure where each block contains previous hash along with current transactions value. In my own imagination, i personally imagine it as an interlocking puzzle with tailored connecting pieces that consists of the past, current, future pieces
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#4163
  1. This ensures the finality principle. Because blocks are linked together, changeing one block requires you to change all following blocks which requires an inordinate amount of computing power (which is not practically possible).
  2. Transactions, previous hash, nonce, target diifficulty, version, timestamp.
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#4164

1: Blocks are linked together cryptographically to secure the network, and to ensure no double spending occurs on the blockchain.

2: The structure is as follows: The hash of the block, based on the transactions contained therein, plus the previous hash, and the nonce that is the subject of being guessed.

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#4165

  1. It is crucial for the blocks to be cryptographically linked together for the safety of the blockchain and to deter anyone from gaming the system. When each block’s hash is linked to the previous block, it offers immutability and thus it is infeasible for anyone to make changes in a block once it’s been constructed.

  2. BTC block structure consists of the following:
    a) A unique block hash;
    b) Hash of the previous block;
    c) data (selected list of TXs); and,
    d) Nonce.

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#4166

  1. that way the network is secured and cannot be changed, because a change destroyes all the following links and blocks.

  2. previous hash, the data or list of TX, inputs outputs, nonce

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#4167
  1. If one block is changed, it would invalidate the blocks that follow and so on.
  2. The block contains the information of the present block plus the hash before and a nonce that the miner has to guess.
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#4168
  1. the link insures no one can change a previous transaction.
    2.a chain. blocks link togeter by a chain to a previous block
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#4169
  1. Because effecting one effects them all which makes it more secure.
  2. Tx Fee, Previous Hash, Nonce. All that together forms a hash for that block.
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#4170

  1. To prevent double spending by maintaining connected blocks which share the ledger/data.

  2. A BTC block contains previous hash, Tx details and a nonce number.

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#4171
  1. Why is it important that the blocks are cryptographically linked together : If blocks are linked together in the blockchain, it means that all subsequent blocks were successfully hashed from previous blocks and thus all transactions in the next block is linked to transactions that was processed in the previous blocks. This means that the blockchain is secure and that the integrity of the transactions can be proven.
  2. What does the block structure look like in bitcoin : Each Block has a hash number that is a function of the hash number of the previous block, the transactions in the new block and the nonce. I.e. Hash(New) = F(Hash(Prev), TX, Nonce)
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#4172
  1. Having the blocks cryptographically linked together ensures that the transactions in a block cannot be changed without invalidating each proceeding block in the chain
  2. Each block in Bitcoin is comprised of a unique hash, a nonce, a list of transactions, and the unique hash of the previous block
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#4173
  1. Linking the blocks together by including the hash of the previous block in the current block is a key security feature of the bitcoin blockchain and guarantees its immutability. If a transaction (or other data) in an older block is changed, the link to all following blocks is broken, because the hash of that block changes. Since that hash is included in the next block, the hash of the next block changes as well. And so on. This means previous blocks cannot be changed unless you re-mine all following blocks. This also means the further a block is in past, the more difficult it is to change, because more blocks need to be re-mined.
  2. List of transactions, hash of previous block, and nonce (this is based on what is mentioned during the lecture. There might be other data included in the header. Potentially, block height, time, block reward etc.?)
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#4174

It is based on math physics protocol, consensus algorithm which produces its own digital finger print.

Each block linked together contains nonce, data (transactions), previous hash and the targeted hash to be linked to the blockchain.

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#4175

1 - Besides immutability and traceability, blocks are cryptographically linked to assist in mining of the next block

2 -
Block Number
Nonce
Data within
Previous Hash
New Hash

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#4176
  1. This secures the network in that, any attempt to make changes or double spend will break the whole chain of blocks forward. if the person would want the changes to persist, he would have to remine and create a longer chain forward, which is impossible practically.
  2. a block is made up of
    a) block hash, derived from:
    b) previous block hash, transaction list and the Nonce(Random number used to create an accepted hash.
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#4178

  1. Each link is the hash of the previous block, to break one would require to re-mine all the previous blocks and keep up with current blocks. These links are key to Bitcoin’s immutability.

  2. Previous Block Hash
    Transactions
    Nonce

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#4179

Why is it important that the blocks are cryptographically linked together?
One block is dependent on the other where each block is hashed. If one block is altered
the whole link is broken. This helps ensure the integrity of the network. Without this
cryptograpgic link, it would be possible to change and amend the blockchain, thus
invalidating the integrity of the blockchain.

What does the block structure look like in bitcoin?
Noonce(random generated no), hash of previous block and list of transactions

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#4180
  1. So that the integrity of the network is there. Basically if you unlink part of the chain, the current hash will change and make the blockchain invalid.
  2. Previous Block Hash + TXs + Nonce
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