You have been provided with a wallet and a blockchain with a genesis block similar to the following.
The genesis block contains one special transaction that does not have any inputs, and which gives you 100 coins. The genesis block is a special block, being the first one, its reference to the hash of the previous block is “0”. Also, the Merkle root of the genesis block is the same as the hash of the only transaction in the block. The transaction in the genesis block is sent and signed by a special wallet, referred to as the coinbase.
The exercise consists of adding two blocks to the blockchain:
1. The first block should comprise of two transactions:
• You sending 40 coins to Alice,
• You sending 30 coins to Bob.
2. The second block should comprise of two transactions:
• Alice sending 20 coins to Bob,
• Bob sending 10 coins to You
Report Please answer the questions briefly and in your own words. Use diagrams where possible and explain them. Copy-pasting Wikipedia articles or verbose explanations will not get you very far. Wherever you are asked to provide an example, do so with references to fields and figures in the exercise.
Explain briefly what is meant by Blockchain being referred to as: "Ledger - Trust + Cryptography".
In general terms, how does sending coins in a cryptocurrency work? What is the send-to address? Which fields make sure – and how – that transactions cannot be altered by nodes on the network? 5
What are the inputs and the outputs of a transaction? Instead of a ledger of balances, what do nodes actually keep track of? What does it take to figure out your own balance?
What is double spending?
What is the difference between a transaction chain and the block chain?
Which field stops the ability of nodes on the network to duplicate transactions?
Describe briefly how Merkle Trees help in pinpointing a mismatching transaction between two blocks without comparing each and every transaction.
How do all nodes on the network arrive at a consensus with regards to the ordering of transactions?
Explain briefly what it would take for Alice to defraud Bob and how Bitcoin prevents this.
What would happen if 90 per cent of miners were suddenly shut out of the network for a prolonged period?