Homework on Blockchain and Mining Visually - Questions

Blockchain and Bitcoin 101
#985

  1. The blocks are linked together to make the network more secure and immutable. It prevents you from changing data from previous blocks because it would break the chain.

  2. A block contains the nonce, the hash from the previous block, and all the transactions within the block.

1 Like
#986
  1. So it would be hard for someone to go back and change it, so it would be more profitable to stick by the rules, mine new blocks rather then going back and change them.
  2. The hash of all the transactions in that block, the hash of the previous block and the nonce that the minor needs to guess.
1 Like
#988
  1. Why is it important that the blocks are cryptographically linked together?

It is important because it keeps the network more secure, prevents double spending and if something is changed we would know right away.

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

A block contains a hash of the previous block, all transactions from that block and a random number (nonce).

1 Like
#989

The previous block hash is included in the creation of the new block. Maybe that is what you meant?

The block hash, so both blocks are cryptographically linked!

1 Like
#990
  1. To make sure it is immutible and unchanging. If they were to go back in time to change a block they have to change all subsequent blocks making it almost impossible to get that much hash power as time goes on.
  2. it has the block version, the previous hash, the nonce, the transactions, current target
1 Like
#991

Maybe not the the blocks, but previous block hash and list of transactions.

#992

  1. It is important for blocks to be cryptographically linked together so the security of the blockchain is attained.

  2. The block structure for BTC consists of:
    The previous block hash
    Transactions
    Nonce

1 Like
#993

Task in Blockchain and mining visually - Questions

Why is it important that blocks are cryptographically linked?

When the blocks are cryptographically linked, the digital information is distributed on the blockchain but cannot be copied, this condition guarantees the immutability of the data contained in the blocks.
The distributive nature of the blockchain database implies that it is unalterable

What does the block structure look like in bitcoin?

Version, hash of the previous block, timestamp, hash merkle root, nonce, bits

1 Like
#994

Thanks Wafflemakr… much appreciated …Yes the “previous blocks” hash is included in the creation of the new block.

1 Like
#995

  1. So they are immutable and no cheating can be done by someone trying to change the info in a previous block.

  2. hash of previous block + tx list + nonce

1 Like
#996
  1. for the security of the blockchain. That way no transactions can be changed in previous blocks because it would break the link to the next block and all that follow.
  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.
1 Like
#997

To make it difficult to corrupt and or change the data. Not impossible but introduces a high probability of making it impossible. Therefore making the data immutable

The nonce used when creating the hash linkage
A hash of the transaction that took place
The hash of the previous block.
And finally the hash of all those above (that will become previous hash of the next block)

1 Like
#998
  1. no tx can be cchanged in prev blocks because it uld break the lnk to the next block and after
  2. block#, nonce guess, data tx, previous hash = hash
1 Like
#999

  1. To make the data immutable

  2. A block which contains Previous Hash, Transaction Data and Nonce. Add those 3 items and Hash it and repeat.

1 Like
#1001

Homework on Blockchain and Mining Visually - Questions

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

1.The links on the blockchain, links all block together. The links are cryptographic puzzles that are required to be solved by the miners. When miners solve the puzzle, there block is linked to the existing blockchain. This part is one process of Proof of work eco system. If anyone tries and change a previous block, the link (cryptographic puzzle) would change. This in turn will change block structure and have a knock on effect with all the other blocks. But in practicality to change something in a block, such hashing power is required which a lot of electricity. This would also mean that other miners will continue to add more blocks to the chain. To have a block changed and want to rest of the network to recognise as correct data in the blockchain, you will have to change every block after the required block you changed. This much electricity being used for this task would be money lost, so being honest and using the hashing power and be a miner would be a better incentive and profitable.

What does the block structure look like in bitcoin?

2.A block structure in a Bitcoin Blockchain has Several properties. Some of the key information in block are:

  • Transactions list
  • Previous Hash
  • Nonce ( a random number that is guessed by miners using hashing power. This is also the cryptographic puzzles that miners have to solve)
  • Hash ( This Hash output has a target that it hit. The hash output has to be less then what ever the target is at the time. The target is set depending on the number of miners are mining at the time. The protocol on the bitcoin blockchain is set that when the more miners are mining the lower the target is set. The less miners then the higher the target is set. To co balance this in the POW Eco system, when the target is low due to high number of miners then the harder the Nonce puzzle will be. And in return the target becomes higher. in balance the nonce puzzle becomes easier to solve.
1 Like
#1002
  1. the chain structure ensures that the entire transaction history is in the correct order in one place and that every small manipulation becomes immediately obvious through the cryptographic link
  2. hash / TX list / previous hash / nonce
1 Like
#1003

Homework on Blockchain and Mining Visually - Questions
** Why is it important that the blocks are cryptographically linked together?**
** What does the block structure look like in bitcoin?**

  1. The blocks are cryptographically linked together for the prevention of any changes to or deletion of transactions in all blocks that are already confirmed.

  2. The block structure in bitcoin consists of –

  • A hash, which is a function of the hash of the previous block, the nonce, and a list of transactions to be added to the blockchain
  • The list of transactions
1 Like
#1004

  1. It is important that blocks are cryptographically linked together for the security of the blockchain.

  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.

3.The block is made out of data, from a current hash, previous block hash and a nonce, with a target to obtain. The lower the number the more difficult to solve the problem.

1 Like
#1005

1.) Having the blocks cryptographically linked together keeps the data secure, prevents alteration of data, deletion of data, basically it keeps things honest.

2.) A Bitcoin block contains the hash of the current and previous block, block size, transaction data and nonce.

1 Like
#1006
  1. Why is it important that the blocks are cryptographically linked together?
    When the blocks are link together sequentially and cryptographically if you change any of them it will affect the rest make it harder to alter which make it more secure.
  2. What does the block structure look like in bitcoin?
    Previous hash,current transactions, nonce and the current hash based on all the above.
1 Like