Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#4322

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

  • because it secures the network and verifies that the transactions in the blocks are correct and valid

What does the block structure look like in bitcoin?

  • Block #, Nonce, Data (transactions), previous hash, and current hash
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#4323

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

By linking new transaction block hashes to the earlier transaction block hashes, together with the transaction data in the block which the miner is making, and with a random nonce that needs to give a hash number lower than the target number, blocks are so strongly connected to each other, that it is extremely difficult for a single computer to change previous transactions on the blockchain. When even a single earlier transaction is changed, the following blocks, and the links which connect the blocks, are no longer correct, and can therefore be easily rejected by most of the BTC network. This increases network security, since these cryptographic links prevent fake transactions, by making them extremely difficult.

What does the block structure look like in bitcoin?

The BTC blockchain database is a series of blocks of digital transactions, connected to each other with cryptographic hashes. These hashes are strongly connected by being based on earlier transaction groups within the blocks, together with earlier block hashes, and random numbers called “nonces”.

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#4324

Why is it important that the blocks are cryptographically linked together?
It is important to ensure imutability.

What does the block structure look like in bitcoin?
Previous block hash, current block data and nonce.

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#4325

  1. It is important that the blocks are cryptographically linked together because it secures the blockchain network, exponential hash rate power, it is immutable, no double-spend, no censorship.

  2. The block structure in bitcoin looks like a chain of blocks each having their own hash as well as the hash of the previous block and a nonce and so-on to make it difficult to decipher.

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#4326

  1. It is important because that is what keeps the network secure. If it was easy to separate out blocks and alter them individually it would be less secure. It’s like a house of cards, you can’t take a lower card out without it effecting all the other cards.

  2. The blocks have the hash from the previous block, transaction list, and the nonce. Linked to the next block by the hash that was below the target.

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#4327
  1. The link insures the integrity of the blockchain through each block’s hash value being included in the generation of the next block’s hash value.
  2. The bitcoin block structure looks something like this:
    {
    Nonce
    Transaction data[]
    this blocks Hash value
    previous blocks Hash value
    }
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#4328

Homework on Blockchain and Mining Visually - Answers:

  1. The blocks are cryptographically linked together for the security of the network. It makes practically impossible to change or delete block data.
  2. In bitcoin the block structure consists of a nonce, limited by block size data, the previous block hash and the hash of all these elements.
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#4329
  1. It’s important that the blocks are cryptographically link because it helps to protect the Blockchain integrity, make sure people cannot double spend.

2.the blockchain structure looks like
Txn
Hash
Nonce.

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#4330

  1. Why is it important that the blocks are cryptographically linked together?
    To avoid cheaters change the previous blocks so easily without consequences. It keeps the blockchain very secure and hard to manipulate without losing so much effort, money, and electricity.

  2. What does the block structure look like in bitcoin?
    It is a block comprised of transaction list, previous hash, and nonce -> that makes up the new hash for the current block.

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#4331

  1. To maintain integrity of the network and make sure that the data of a block cannot be changed because if some data changes then that block and all the following blocks would not be valid anymore - they would have to be re-mined which is practically impossible.

  2. Hash from previous block + nonce (number guessed by miners) + the data of this block - the nonce should be such that the hash of the block is below the target hash number.

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#4332
  1. It prevents transaction history from being altered
  2. Each block contains the hash of the previous block, the winning nonce and transaction data, as well as the current block hash which results from all of these
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#4333
  1. Because this keep the network secure.
  2. The block is made by hash, previous hash, tx list and nonce
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#4334
  1. This happens because the Hash is also based on the hash of the previous blok in the blockchain. This makes it impossible to changes previous bloks (the transactions in that blok), because then that blok and all the bloks that follow in the network need to be remined.
  2. The Hash is based on the prev hash, the data in the new block and the nonce. The nonce is a random number that needs to be guessed and that needs to be below the target. When this happens the new hash gets accepted and can be send to the nodes.
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#4335

-it is important that the blocks are linked together because it helps prevent the inputs and outputs from being changed.

-transaction,inputs,outputs,hash functions

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#4336

and previous hash which links the new block to the blockchain.

#4337

  1. It increases security of the blockchain and lowers the possibility of foul play. It they weren’t all linked together since the first block, it would be much easier to change data in the blocks.

  2. A new block consists of the hash of the previous block, the data of the current block and a nuance, which are all hashed, creating the hash of the current block, when mined.

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#4338
  1. Blockchain is immutable, trustless, and public because the blocks are cryptographically linked together.
  2. Inside of a single block we have a hash, a previous hash, data/transactions, and nonce.
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#4339
  1. to keep a blockchain (ledger) immutable, secure and comprehensive
  2. block structure could be devided in 3 general groups:
    a) Block Identifiers
    b) Block Header (I think here we would find a nonce, which is kind of most important for miners even tho its changing is automated)
    c) Transactions
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#4340
  1. It gives the blocks a unique finger print.
  2. the hash of blocks consist of transactions and the previous hash and the nonce.
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#4341

  1. By linking the hashes of all blocks to one another it prevents a miner from tampering with a previous block because suddenly the hash for all following blocks will be effected and rejected

  2. All transactions/rewards/fees for that block, a unique hash fingerprint, and a nonce

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