CSIT-802 (D) - Block Chain Technology

Consider Bob the merchant deciding whether or not to accept the $C_1 \to B$ transaction. What Bob is really interested in is whether or not the other chain will catch up? Why, then, does he simply check how many confirmations $C_1 \to B$ has received, instead of computing the difference in length between the two chains?

If a malicious ISP completely controls a user's connections, can it launch a double-spend attack against the user? How much computational effort would this take?

Write a ScriptPubKey that requires demonstrating a SHA-256 collision to redeem.

Write a corresponding ScriptSig that will successfully redeem this transaction.

Speculate about why buying bitcoins in person is generally more expensive than buying from an online exchange?

Moore and Christin observe that security breaches and other failures of exchanges have little impact on the Bitcoin exchange rate. Speculate on why this might be and explain the reason?

Write the four stages of Ethereum development.

What are the components of Blockchain?

Write the structure of Transaction.

What is a Smart Contract? Explain in detail.

Assuming that the total hash power of the network stays constant, what is the probability that a block will be found in the next 10 minutes?

What is the task of bitcoin miners?

Write the advantages and disadvantages of full node.

What are the various wallets and DAPP browsers?

Explain: Merkle trees.

Explain: Cryptocurrencies.

Explain: Double spend attacks.