Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#2352

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

    To make it almost impossible to change the contents of any validated blocks.

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

    Block Number -> Nonce -> Data -> Hash of previous block -> Hash of the current block

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#2353

Because each new block is is cryptographically linked with the last block that was created, it makes it very difficult for someone to change a transaction in a previous block. This makes the blockchain immutable by nature and is a huge contributor to network security.

A block is a package data structure. It consists of the block header, the block size, the transaction counter and the transactions themselves.

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#2354

Do you know what is in the block header? :slight_smile:

#2355
  1. Why is it important that the blocks are cryptographically linked together?

When one block is altered, all the “solutions” to the puzzles, which link the blocks together, will be false. The network will immediately notice.

  1. What does the block structure look like in bitcoin?
    Hash of the current block, previous hash, transaction list of the current block, nonce
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#2356

  1. So there can be no way of tampering with the past data. Integrity. It’s a chain, blockchain.

  2. A nonce, the data, and the previous block’s hash.

2 Likes
#2357
  1. It is the concept of Blockchain (immutable and cencorship-resistant)
  2. Block Hash, Block size, Transaction Hash, inputs, outputs
1 Like
#2358

Why is it important that the blocks are cryptographically linked together?
A: It provides IMMUTABILITY of the blockchain. Any alteration would break the links so the network rejects any attempt to change a block.
What does the block structure look like in bitcoin?
A: It is a group of transactions with a hash linked to the previous block and a nonce. All of these are linked together cryptographically into a final hash that is used as a link to the next block.

#2359

Homework on Blockchain and Mining Visually - Questions

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

A. Ensures block remains immutable and secure.

  1. What does the block structure look like in bitcoin?
    A. Appended block counter
    Nonce #
    Data Tx’s List
    Hash of previous block
    and “Mine” button
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#2360

Sure do :smiley: :

The block header is where the previous block hash is found, along with some information relating to the mining process like the nonce that was used, the difficulty target and a timestamp of when the puzzle was solved.
It also contains something called the ‘merkle root’, which is essentially a hash of all the transactions found in that block.

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#2361

There are no buttons on the blockchain :stuck_out_tongue: not sure what you meant by that

#2362
  1. It is important blocks are cryptographically linked together because it makes it continuously more difficult to change a block and upholds the immutability of the network. If one is changed then they all must be changed. This increases the integrity of the network exponentially.
  2. A block in bitcoin is comprised of transaction data, the hash of the previous block, and a nonce (number only used once) to produce a hash that is below the target hash.
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#2363

  1. To make it impossible to change any record. If you change one all subsequent links break.

  2. Any block has its transactions, the hash from the previous block, and a nounce, which is a random number. All together conform the new hash, so miners have to guess the nounce and receive a hash lower that the target.

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#2364

1 This secures the blockchain and ie strengthens the network.

2 A transaction list of blocks including input and output hashes.

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#2365
  1. in Bitcoin the data is stored in blocks of approximately 1MB or less each and are linked together and makes it immutable. Without this secure way to link Bitcoin would be in kaos,
  2. Header, block, nonce, previous, hash, mine. not sure this is what you wanted. let me know thx.
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#2366
  1. To ensure the security of the data because in case of an alternation this link breaks.
  2. The block contains the hash from the previous block, list of transactions and a nonce.
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#2367
  • Why is it important that the blocks are cryptographically linked together?
  • What does the block structure look like in bitcoin?
  1. To ensure the security and immutability of the blockchain.
  2. The previous hash, transactions and the nonce.
1 Like
#2368

  1. It is important that the blocks are cryptographically linked together to ensure security of the network by making it very difficult to change the contents of a block in the chain.

  2. The block structure in bitcoin consists of the transaction list being added to the chain, the hash of the previous block, and a random number called a nonce.

1 Like
#2369

1 - Assures blockchain immutability. Prevents confirmed transactions from being altered.

2 - The data in a Bitcoin block includes a block size, block header, transaction counter, and transactions. The block header includes the version, the previous block hash (of parent block), merkle root, time stamp, difficulty target, and nonce. The merkle root is a hash of the merkle tree (binary hash tree): a cryptographic data structure of the entire set of interlinking transactions.

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#2370

A block has a list of only the current txs and the tx is hashed to get the txid. From these txids a merkle tree is constructed and the root of the tree is used in the block hashing process along with the hash of the previous block. :slight_smile:

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#2371

1.blockchains are cryptographically linked together to ensure the integrity of the blockchain.
2. the block structure contains the previous hash, the current hash, and the nonce.

1 Like