Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#2532

You forgot to mention the hash from the previous block that links the blocks in a chain :wink:

1 Like
#2533

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    • This assures if any link in the chain is compromised then all links\blocks after this link will also be compromised. This in itself prevent fraud and manipulation. This link also prevents a double spend or money being spent twice.
  2. What does the block structure look like in bitcoin?
    • Previous hash of block in the blockchain(if it exist)
    • Links to all transactions in the block
    • Nonce
1 Like
#2534
  • Why is it important that the blocks are cryptographically linked together?

It creates a strong security on the network because it assures that if you change any previous data in the blockchain then all hashes after that also change so this checks for the integrity of the data (truth) in the network.

  • What does the block structure look like in bitcoin?

Transactions
Hash of previous block
Nonce
Hash of the above to hit target

1 Like
#2535
  1. Why is it important that the blocks are cryptographically linked together?
    • This is how the blockchain stays secure. Blocks contain transactions that are verified to be true. If a person tries to change the transaction, it will change the block’s hash and the blocks that are linked to it. This notifies that a invalid action has been made.
    • This makes sure that the integrity of the blockchain stays consistent.
  2. What does the block structure look like in bitcoin?
    • Block structure = Hash value = nonce + list of transactions + previous hash value
      If any of the values change the block structure is not the same.
1 Like
#2536

  1. It is important because this greatly improves the blockchain’s security. It makes double-spending practically impossible to perform.

  2. A block structure is constructed by the following.

  • The hash from the previous

  • The list of transactions in the current block

  • A nonce number

  • The hash of the current block

1 Like
#2537
  1. It make the changes in the previous block impossible to change, alter etc. It’s to keep the network secure, to avoid double spending, to make sure it’s uncensored.
  2. Previous block’s hash + transactions + nounce
1 Like
#2538
  1. If one block is modified, the cryptographic link will get broken so it will be easy to spot the breach.
    It ensures the immutability of the blockchain.
  2. The block is comprised of the hash of the block ,transactions, the hash of the previous blocks & the nonce.
1 Like
#2539

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

    -it makes them secure, because if someone wants to change a transaction on the block or double spend or something similar, it’s impossible for them to do this, because then they would need to re-mine all the following blocks

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

    -previous block’s hash + transactions list + nonce

1 Like
#2540

Homework on Blockchain and Mining Visually - Questions

  1. Why is it important that the blocks are cryptographically linked together?
    So that it is difficult for someone to change previous blocks and therefore the network is more secured.

  2. What does the block structure look like in bitcoin?
    previous hash plus transactions plus nonce which leads to current or next hash and block that then becomes the previous hash of the next block

1 Like
#2541
  1. Why is it important that the blocks are cryptographically linked together?
    so that previous blocks cannot be changed without improbable amount of computational power
  2. What does the block structure look like in bitcoin?
    it contains inputs and outputs addresses, amounts as well as the block’s hash
1 Like
#2542
  1. It creates immutability so that no one can change what has transpired.
  2. Blocks are created by Hash’s that rely on the previous block, the size and type of transactions, and a nonce - which is a random number generated by the algorithm which then becomes solidified as part of the next block.
1 Like
#2543

  1. Every block contains a hash of the previous block. This has the effect of creating a chain of blocks from the genesis block to the current block. Each block is guaranteed to come after the previous block chronologically because the previous block’s hash would otherwise not be known. Each block is also computationally impractical to modify once it has been in the chain for a while because every block after it would also have to be regenerated. These properties are what make bitcoins transactions irreversible. The block chain is the main innovation of Bitcoin.

  2. Each block contains, among other things, the current time, a record of some or all recent transactions, and a reference to the block that came immediately before it. It also contains an answer to a difficult-to-solve mathematical puzzle - the answer to which is unique to each block.

1 Like
#2544

1 For the security of the networrk.
2 link from block to hash

1 Like
#2545
  1. Why is it important that the blocks are cryptographically linked together?

Linking the blocks by hashes makes it almost impossible to do any change in the history of blockchain.

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

A block has the hash of the previous and current block, the list of transactions to that block, a number called a nonce, amount of transactions, summaries, fees, times, sizes, versions and rewards.

1 Like
#2546

  1. Why is it important that the blocks are cryptographically linked together? It’s important because cryptographically the links only goes in one direction, and cannot be reverse engineered. And the information that the link is carrying forward is the consensus truth.

  2. What does the block structure look like in bitcoin? The block structure consist of nonce, data on the block, and previous hash.

1 Like
#2547

Homework on Blockchain and Mining Visually - Questions

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

As discussed before, it is almost impossible to change data in a previous block.
The cryptographic part is fundamental for security.

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

Nr of Block
Time and Date
Nonce
Data
Hash of the previous Block
Hash of this Block

1 Like
#2548
  1. It makes it hard to temper with existing data.
  2. Transaction data, hash of the previous block, hash of a current block and nonce.
1 Like
#2549
  1. So one cannot replace just 1 block. As they are linked, that action would invalidate all following blocks, therefore the chain would be shorter and ignored.
  2. a. The guessed “random” nonce.
    b. The list of transactions starting with block rewards.
    c. the previous’s block hash
    d. I guess some other details like header, difficulty, blocksize or blocknumber…?
1 Like
#2550

Homework on Blockchain and Mining Visually:

Q1: Why is it important that the blocks are cryptographically linked together?

A: It’s important that the blocks are cryptographically linked together to deter attempts to alter data in any blocks on the blockchain, ensuring the security and integrity of the blockchain network.

Q2: What does the block structure look like in bitcoin?

A: The block structure in bitcoin looks like, and consists of a nonce, tx data, previous block hash, and current block hash.

1 Like
#2551

  1. Why is it important that the blocks are cryptographically linked together?
    Ans 1: By cryptographically linking all of the previous blocks and the current block that is being appended onto the network, helps with the integrity of the data and in securing the network. This ensures that previous data is not tampered with and that the network is trust-less & verifiable using maths and physics.

  2. What does the block structure look like in bitcoin?
    Ans 2 : Previous block hash, Current transactions and nonce mainly.
    :pray: :heart: :pray:

1 Like