Blockchain CBSA Practice Test - Questions Answers

Reference: https://blockgeeks.com/guides/hypothetical-attacks-on-cryptocurrencies/

Reference: http://www.btcsatoshi.com/ http://ethdocs.org/en/latest/ether.html

Proof of Stake has the same goal as proof of work"”to validate transactions and achieve consensus in the chain"”and it uses an algorithm but with a different process. With proof of stake, the creator of a new block "is chosen in a deterministic way, depending on its wealth, also defined as a stake." Since in a proof of stake system, there is no block reward, but the miners, known as forgers, get the transaction fees. Proponents of this shift, including Ethereum cofounder Buterin, like proof of stake for the energy and cost savings realized to get to a distributed form of consensus.

Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read

A Byzantine failure is the loss of a system service due to a Byzantine fault in systems that require consensus. Reference: https://en.wikipedia.org/wiki/ Byzantine_fault_tolerance

Stream cipher basically means using a fixed key which replaces the message with a pseudorandom string of characters. It is basically the encryption of each letter one at a time.

Reference: https://blockgeeks.com/guides/cryptocurrencies-cryptography/

A search engine that allows users to easily lookup, confirm and validate transactions that have taken place on the Ethereum Blockchain

Reference: https://etherscancom.freshdesk.com/support/solutions/articles/35000022140-what-is-etherscan-

Reference: http://www.hl.co.uk/news/2018/2/16/a-brief-history-of-blockchain-technology-everyone-should-read

Sometimes referred to as "private" blockchains, you are required to have some sort of permission to access any or parts of that blockchain. There are a multitude of variants and hybrid permissioned/permissionless blockchains that exist.

Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchains-acb8661ee095

BFT is so-named because it represents a solution to the "Byzantine generals' problem," a logical dilemma that researchers Leslie Lamport, Robert Shostak and Marshall Pease described in an academic paper published in 1982

Reference: https://www.nasdaq.com/article/byzantine-fault-tolerance-the-key-for-blockchains-cm810058