Homework on Blockchain and Mining Visually - Questions

[Romaink]

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

Precisely because this is what makes it possible to have an immutable time-stamped distributed register in its past recorded data thanks to the block chain, which makes the network insensurable, traceable and viewable by all, and this, from the first block issued. All of this encompasses exceptional security thanks to the attraction of miners for block rewards, the strongly disinflationary mechanism as well as the limited supply that makes up the economic interest of wanting to mine and keep its Bitcoin since necessarily ensuring its scarcity both in number than in its production.

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

The structure of a BTC block consists of a database of transactions, a header hash representing the difficulty target of the mathematical solving game closest to the Golden nonce, as well as the hash of the previous block to link the block to the previous one and the previous one to the previous one …

[Nedu]

1. Since there is no central authority, linking the blocks cryptographically together ensures security and integrity as it is practically impossible to alter a previous transaction

2. The major items are previous hash; transaction list and nonce.

[Slavy]

1. Because of the security.
2. TX hash, input, output

[56butch]

1. Cryptography creates unbreakable chains within the blockchain.
   And the blocks are secured and linked together with the miner’s
   proof of work.

2. Transactions grouped together in blocks creates the structure
   of bitcoin. And miner’s using SHA-256 further secures the bitcoin
   network.

[abelhingle]

1
It is important for the blocks to be cryptographically linked together so that if someone changes a previous block it would not add up for all of the following blocks. therefore the system would reject it.

2
The block structure is a math problem of the Current blocks transactions, the previous blocks hash and a random nonce that will make the hash lower than target. The target is a number that depends on the difficulty of the network.

[Yann]

1. Why is it important that the blocks are cryptographically linked together? It ensures blockchain security/immutability. One cannot change a block without changing all the blocks after that block within the network.
2. What does the block structure look like in bitcoin? Block #; Nonce; Tx Hash; Hash previous block; hash current block (and also difficulty target, block size;)

[Nate]

1. It is importuned that the blocks are cryptographically linked together to make the net work more securer.
2. The hash is based on the previous block and the hash for this block also have the nonce, transaction data, size,and block number.

[spicydumpling]

1. Why is it important that the blocks are cryptographically linked together?
   • To make the network secure. Changing one thing in the past would require remining all future transactions
2. What does the block structure look like in bitcoin?
   • A series of hashs, each consisting of a hash of the previous blocks

[RayUtik]

1. The block has a context that can’t be changed. Links based on puzzle (previous tx). So each block has a hash, tx list, nonce of the previous block and secured with the link which contains that data.
2. Block number >nonce>data>previous tx>hash of current tx

[Lena_Ghuraibi]

1. to ensure and verify the security. Also to make sure there isn’t any cheating or double spending and that is achieved by showing that if one block is altered, then all the blocks that come after it will be ruined.

2. the block includes its number, the hash of the block and the hash of the previous block, the list of transactions, and the nonce.

[Kaiulan]

1. for security. This will make sure nothing in the previous block will get changed otherwise the link to all the previous block will break as it will change the hash and it would have to be remined and cost much more then get return. Thats why miners rather play by the rules.

2. hash, transactions and nounce (random number)

[Hanibal]

1.So that if anyone tries to change the data of any previous blocks to cheat himself money. The system automatically notices because all of the Date would change. This makes it extremely hard/impossible, for anyone to cheat the system.

2. Every block has it’s own transaction list. The hash of the previous block and the nonce. Which is a random number.

[MKrag]

1. It is important that blocks are cryptographically linked together because that means that altering any single past transaction will sever the link to all succeeding blocks. That adds security to the blockchain by making it practically impossible to alter a past transaction and have it accepted by the network,

2. hash + transaction list + nonce —link–> previous hash + transaction list + nonce --etc–>

[Attiss]

1. Why is it important that the blocks are cryptographically linked together?
   Immutability - changing anything in a previous block will invalidate the hash of subsequent blocks. This is the key to creating the “digital stone” in which data can be added but never taken away or changed.

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

[AverageJoe]

1. Because it ensures that transactions and/or blocks cannot be removed or changed. Essentially it means the blockchain retains its integrity.

2. Block Number > Nonce > Transaction List > Previous Block Hash > Current Block Hash

[BlackPearl]

1. The blocks are linked together in a logical way. If something changes in the block the links are broken and you have to remine them again
   2.The hash of the block is based on the transactions in the block plus the previous hash and the nonce that needs to be guessed.

[Ayajib]

1. It is important that the blocks are cryptographically linked together because it increases the security of network. When one of the previous block needs to be changed all the block preceding that also needs to be changed which is near impossible.

2. Block structure in bitcoin has block number, nonce, transaction data, hash of the previous block and hash of current block.

[Gulaman]

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

2. What does the block structure look like in bitcoin?
   Magic no
   Blocksize
   Blockheader
   Transaction counter
   TXNs

[MichaelW]

1. Why is it important that the blocks are cryptographically linked together?
   To make the blockchain more secure and reliable.
2. What does the block structure look like in bitcoin?
   Previous block hash, current block data and nonce.

[GoldenMantis]

1. To ensure the network is secure and verifiable.
2. Previous block hash, transactions, and the nonce.