How Blockchains Work | The Crypto Asset Pro

Question 1 of 5

What is a hash in the context of blockchain?

A A type of cryptocurrency B A fixed-length fingerprint produced from data by a mathematical function C The speed of a transaction D A mining reward

A hash is a fixed-length output from a cryptographic function. The same input always produces the same hash, but changing any part of the input completely changes the output.

Question 2 of 5

Why is it almost impossible to alter a historical blockchain transaction?

A Governments prevent it B Changing one block would require recalculating every subsequent block faster than the entire network adds new ones C Blockchains are stored on secure servers D Transactions are encrypted with a password

Altering any block changes its hash, which invalidates the next block, which would need to be recalculated, and so on requiring more computational work than the entire honest network.

Question 3 of 5

What is a node?

A A type of crypto wallet B A computer that stores a copy of the blockchain and validates transactions C A mining machine D A blockchain transaction

A node is any computer running the blockchain software and maintaining a full copy of the chain. Thousands of independent nodes validate and store Bitcoin's history.

Question 4 of 5

In Proof of Work, what do miners compete to do?

A Create the most transactions B Solve a complex mathematical puzzle to add the next block C Hold the most Bitcoin D Build the fastest computer

In Proof of Work, miners compete to solve a computational puzzle. The winner adds the next block to the chain and earns the block reward.

Question 5 of 5

What does "immutability" mean for blockchain data?

A Data can be changed by administrators B Data is stored temporarily C Once confirmed, data cannot practically be altered or deleted D Data is private and encrypted

Immutability means confirmed blockchain transactions are permanent. The chain's structure makes retroactively altering data computationally infeasible.