30 Questions
What is the purpose of nonce in the process of proof-of-work?
To act as a counter for miners to modify and get the desired hash
How does Hashcash system prevent email spamming?
By requiring senders to perform computational work
In a blockchain, what is used to resolve disagreements or chain forks?
Longest chain rule and Proof-of-work
What is the purpose of payload in a block?
To hold the actual data or transactions to be stored in the block
How do miners decide which chain to work on when multiple chains exist?
By following the longest chain rule and proof-of-stake
What role does Proof-of-work play in ensuring trust among miners?
It establishes a competitive environment and trust between anonymous miners
What happens in a tie situation when multiple chains have equal work done?
The blockchain keeps working until one chain has more work done
What is the main motivation for miners to perform computational work in blockchain?
To earn cryptocurrency rewards by adding blocks to the chain
What do miners modify to achieve the desired hash in proof-of-work?
The nonce value in the block data
How does blockchain validate new blocks using headers?
By confirming that the previous block's hash matches with its own header hash
What is the purpose of the nonce in the process of proof-of-work?
It acts as a counter that miners change to find the correct hash.
How does the blockchain resolve disagreements or chain forks?
By following the longest chain rule and choosing the chain with the most work done.
What motivates miners to perform computational work in blockchain?
Earning additional coins for solving complex puzzles.
What is included in a blockchain to enable checking the validity of a new block using headers?
Nonce and a summary of payload
Which element serves as a counter and is usually initialized at zero in hash cash?
Nonce
In blockchain, what happens when there is a tie situation where multiple chains have equal work done?
Blockchain keeps working until one chain has more work than the others.
What impacts a miner's decision on which chain to work on when multiple chains exist?
The chain that has accumulated the most work.
How does Hashcash system prevent email spamming?
By making email senders perform computational work before sending an email.
What is the role of payload in a block?
To store important data or transactions in a block.
How do miners achieve the desired hash in proof-of-work?
By modifying the nonce value until a valid hash is found.
What is the purpose of the nonce in hash cash?
To act as a counter for hash calculations
How does the blockchain handle chain forks when multiple chains have equal work done?
It waits for one chain to have more work done
What prevents email spamming through the Hashcash system?
Proof-of-work requiring computational effort
What is the role of payload in a block within a blockchain?
Storing actual data or transactions
How do miners select which chain to work on in blockchain when multiple chains exist?
Selecting the chain with the most work done
What motivates miners to perform computational work in blockchain?
Monetary rewards from solving complex problems
In a blockchain, what enables checking the validity of a new block using headers?
Summary of payload
What is used to resolve disagreements or chain forks in blockchain?
"Proof-of-work" and longest chain rule
How does Hashcash prevent email spamming?
By requiring email senders to perform computational work
What differentiates Hashcash from Proof-of-work in blockchain?
The focus on preventing email spamming
Study Notes
Bitcoin Mining and Blockchain
- Miners are motivated by self-interest to earn rewards and transaction fees by successfully adding a new block to the blockchain.
- Miners verify transactions within a block to ensure they are valid, then spread the newly created block to the rest of the network.
- Each node verifies the new block before starting to mine.
- Miners are rewarded with newly created bitcoins for successfully mining a new block (initially 12BTC, then 6.25BTC, halving every 210,000 blocks).
Bitcoin Block Structure
- Bitcoin uses a transaction-based ledger, where the sender signs the transaction to prove ownership of the funds being transferred.
- A transaction consists of an output (first) and input (then).
- Input is a reference to an output from a previous transaction.
- Multiple inputs are often listed in a transaction, and all new transaction's input values are added up.
- Previous tx is a hash of a previous transaction.
- Index is the specific output in the referenced transaction (0 or 1).
- ScriptSig is the first half of a script, verifying the provided public key and checking the signature against the public key.
Transaction Types
- Pay-to-script-hash: enhances flexibility and security of Bitcoin transactions, enabling more complex spending conditions.
- Pay-to-multi signature: allows users to lock coins with a requirement for multiple parties to sign the scriptSig before coins can be spent.
- Proof-of-burn: sends coins to a burn account, which cannot spend or redeem the coins sent to it.
Node Types
- Fully-validating nodes: permanently connected, store entire block chain, hear and forward every node/transaction.
- Lightweight nodes: store block headers, verify the puzzle was solved correctly, but cannot verify every transaction in each block.
Blockchain Resolving Disagreements
- Uses Proof-of-work and the longest chain rule to resolve disagreements.
- When the chain forks, Blockchain takes the fork with most work (i.e., longest chain).
- When there's a tie, Blockchain keeps working until one of the chains has the most work.
Nonce and Hash Cash
- Nonce is a number used in the process of proof-of-work, modified by miners to get the hash that satisfies the puzzle.
- Hash cash is a system that prevents email spamming by making email senders perform a small amount of computational work to send an email.
- The nonce acts as a counter in hash cash, usually starting from zero.
Learn about the process of mining bitcoins, where miners verify transactions, add new blocks to the blockchain, and earn rewards. Understand how nodes verify new blocks before mining can begin.
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