Blockchain Blockchain Solution Architect CBSA Questions & Answers

• Question 221:

  What are two challenges with using a Proof of Work algorithm? (Select two.)

  A. Mining pools not allowed

  B. Difficulty rate goes done every year.

  C. Expensive

  D. Power Intensive

  Correct Answer: CD

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

• Question 222:

  Your customer is an enterprise that is focused on financial sectors.

  What type of blockchain would this customer likely want specified for their enterprise?

  A. Permissionless

  B. Decentralized

  C. Hybrid

  D. Permissioned

  Correct Answer: D

  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-blockchainsacb8661ee095

• Question 223:

  You currently using the Metamask Chrome plugin and you see a selection for Etherescan in the plugin.

  What is Etherscan used for?

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

  B. A search engine that allows users to easily lookup, confirm and validate transaction that have taken place on the Bitcoin Blockchain

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

  D. A search engine that allows users to easily lookup, confirm and validate transaction that have taken place on any Blockchain

  Correct Answer: A

  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-isetherscan-

• Question 224:

  A ____________cipher basically means it is 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.

  What is the cipher type?

  A. Stream

  B. Block

  C. Parallel

  D. RSA

  Correct Answer: A

  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/

• Question 225:

  A Byzantine failure is the loss of a system service due to a Byzantine fault in systems that requires________.

  What is required?

  A. Consensus

  B. Crypthography

  C. Bandwidth

  D. Availability

  Correct Answer: A

  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

• Question 226:

  How many satoshis are in 1 bitcoin and how many wei in an Ether? (Select two.)

  A. 1,000,000,000,000,000,000

  B. 1,000,000,000,000,000

  C. 1,000,000,000

  D. 10,000

  E. 1,000,000,000,000

  Correct Answer: AB

  Reference: http://www.btcsatoshi.com/

• Question 227:

  In the Proof of Stake(POS) algorithm the miners are really known as ___________?

  A. Notary

  B. Oracle

  C. Forgers

  D. Minters

  Correct Answer: C

  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 co-founder 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-shouldread

• Question 228:

  What type of attack would be considered a very large flaw in public blockchains such as Bitcoin's Blockchain where the majority of hashpower could possibly be controlled thru an attack?

  What is the specific attack Bitcoin could be exposed to?

  A. 51% Attacks

  B. Tether Token Hack

  C. DDoS Attack

  D. BIP attack

  E. Parity Wallet Attack

  Correct Answer: A

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

• Question 229:

  SHA-1 is the most commonly used SHA algorithm, and produces a ______-byte hash value(size).

  A. 256

  B. 128

  C. 32

  D. 20

  Correct Answer: D

  SHA-1 is the most commonly used SHA algorithm, and produces a 20-byte hash value.

  Reference: https://www.securityinnovationeurope.com/blog/page/whats-the-difference-between-hashingand-encrypting