Cryptocurrency Blockchain Practice Test 1
Which of the following are real-world Blockchain applications?
Explanation:
The blockchain is a logical technological advancement that is also philosophically progressive, as it transfers power and control of essential information from CEO boards to the general public. If blockchain technology can be developed and expanded to the required degree, it has the potential to eliminate corporate fraud and abuse of power.
On a public Blockchain, who can read the records?
Explanation:
On a public blockchain network, anyone can read, write, and see data. It is impossible to change or delete an entry once it has been confirmed in a public blockchain. Permissioned blockchains are private blockchains.
A block header is made up of which item(s)?
The correct answer:
The hash of the previous block
What happens if two blocks are confirmed simultaneously?
Explanation:
The chain will split if more than one block is validated at the same time. In other words, each node in a blockchain keeps a copy of the database. Let's pretend that two blocks, A and B, were certified at the same moment. After both blocks have been validated, some nodes will receive A first, while others will receive B first.
For cryptocurrencies, which of the following challenges did Blockchain solve?
Explanation:
The fundamental difficulty is that the anonymity-provisioning mechanism must allow other members to verify updates to the blockchain. Most blockchain-based e-cash protocols' pseudonymous feature is insufficient for users to achieve identification and transaction privacy.
Which of the following attacks requires only a single account and only uses standard blockchain operations?
Explanation:
A replay attack can only make an identical transaction in the old blockchain by copying an existing transaction from the new forked blockchain (or the other way around). Remember that transactions received without sufficient replay protection can be replayed months or even years later.
Which of the following methods for generating pseudo-random numbers for smart contracts is recommended?
The correct answer:
External oracle
Which of the following biockchains has an architectural design that is channel-focused?
Explanation:
Hyperledger is an open source collaborative initiative aimed at advancing blockchain technologies across industries. The Linux Foundation hosts a global partnership that includes professionals in finance, banking, the Internet of Things, supply chains, manufacturing, and technology.
What is one typical way for "chaining" pieces of data together in sequence in a blockchain design?
The correct answer:
Store the hash of the previous block within the current block
