Blockchain Blockchain Solution Architect CBSA Questions & Answers

• Question 211:

  What type of encryption is shown below and is commonly used in blockchain cryptography?

  

  A. Diffie-Hellman

  B. Asymmetric Encryption

  C. Synchronous

  D. Asynchronous

  E. Symmetric Encryption

  Correct Answer: B

  Asymmetric cryptography utilizes two different keys, a public key and a private to encrypt and decrypt a particular data. The use of one key cancels out the use of the other.

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

• Question 212:

  Application Specific Integrated Circuit (ASIC) are used always in enterprise blockchains.

  A. TRUE

  B. FALSE

  Correct Answer: B

  ASICS are generally used in blockchains such as BTC that have a Proof of Work consensus due to competition

  Reference: https://www.trymining.com/pages/asic-vs-gpu

• Question 213:

  What are some advantages of Proof of Stake(POS) mining over Proof of Work(POW) mining? (Select three.)

  A. Energy efficient in regards to that it could consume for electricity as compared to PoW

  B. Faster Hashing algorithms

  C. No need for expensive compared to POW

  D. Faster validations compared to POW

  E. Better blockchain security compared to POW

  Correct Answer: ACD

  This eliminates the below challenges from PoW and believed to have an advantage. No need of expensive hardware (a normal laptop or computer running the respective coin's Validator client will do as long as your laptop or computer is online) Energy efficient as it won't consume high electricity as PoW does More loyal Validators As higher the stake the Validators have for a long time, more chances for the Validator to be picked up for "forging" and earn the transaction fee Faster validations

  Reference: https://medium.com/@karthik.seshu/cryptocurrency-proof-of-work-vs-proof-of-stakee1eee1420b10

• Question 214:

  In the Ethereum EVM there are two types of memory areas. (Select two.)

  A. Storage

  B. Database

  C. Memory

  D. Persistent E. Ephemeral

  Correct Answer: AC

  Reference: https://solidity.readthedocs.io/en/latest/introduction-to-smart-contracts.html#the-ethereumvirtual-machine

• Question 215:

  Secure Hash Algorithm (SHA-256) output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes). Select best answer.

  A. NSA is spying on us so what's it matters.

  B. Depends on input

  C. False

  D. True

  Correct Answer: D

  SHA stands for Secure Hash Algorithm. This is used to prove data integrity. The same input(s) will always produce the exact same output. This output is always 256 bits or 32 bytes in length regardless of the length of the input (even if input is millions of bytes).

  Reference: https://medium.com/all-things-ledger/bitcoins-implementation-of-blockchain-2be713f662c2

• Question 216:

  Your company working for is now considering the blockchain. They would like to perform a POC with R3 Corda. The CIO was reading about different blockchain consensus algos and would like to understand what type of consensus algos is used with Corda.

  What is the best answer?

  A. R3 Corda is a pluggable blockchain and allows the enterprise flexibility

  B. R3 Corda is a byzantine fault tolerant blokchain

  C. R3 Corda is a proof of stake based blockchain

  D. R3 Corda is a proof of work based blockchain

  Correct Answer: A

  Corda does not share the same requirements as Bitcoin: we require absolute certainty over transaction finality and we need to know who our counterparts are. So we had the freedom ?and took this opportunity ?to solve the consensus problem in a different way. In particular, Corda solves the privacy issue in a number of manners, primarily by allowing for separation of consensus into a service which we call the Notary Cluster. Corda was designed for business from the start. It has no cryptocurrency built into the platform and does not require mining-style consensus, which imposes great cost with little business benefit.

• Question 217:

  Ethereum is considered to be a ______________type of blockchain.

  A. Permissionless

  B. Permission Based

  C. Hybrid

  D. Private

  Correct Answer: A

  Permissionless - anyone can join Anyone can run a node, run mining software/hardware, access a wallet and write data onto and transact within the blockchain (as long as they follow the rules of the bitcoin blockchain). There is no way to censor anyone, ever, on the permissionless bitcoin blockchain.

  Reference: https://medium.com/@dustindreifuerst/permissioned-vs-permissionless-blockchainsacb8661ee095

• Question 218:

  What is a logic gate in electronics and computer science?

  A. A logic gate usually takes in 2 inputs and gives out 1 output. The inputs and outputs are binary values, meaning they can be both 1 and 0.

  B. A logic gate usually takes in 3 inputs and gives out 2 output. The inputs and outputs are binary values, meaning they can be 1 or 0.

  C. A logic gate usually takes in 2 inputs and gives out 6 output. The inputs and outputs are binary values, meaning they can be both 1 and 0.

  D. A logic gate usually takes in 2 inputs and gives out 1 output. The inputs and outputs are binary values, meaning they can be 1 or 0.

  Correct Answer: D

  A logic gate usually takes in 2 inputs and gives out 1 output. The inputs and outputs are binary values,

  meaning they can be 1 or 0. A XOR logic gate takes in 2 binary inputs and gives out a high output ONLY

  when the inputs are different.

  Meaning, if A and B are inputted to a XOR gate then the out C will be 1 ONLY when A is not equal to B.

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

• Question 219:

  The key difference between encryption and hashing is that encrypted strings can be reversed back into their original decrypted form if you have the right key?

  A. TRUE

  B. FALSE

  Correct Answer: A

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

• Question 220:

  Which is the following is the metaphor that describes a logical dilemma that plagues many computer networks?

  A. Neo Generals' problem

  B. Byzantine Generals' problem

  C. Byzantine Admirals' problem

  D. Renaissance Generals' problem

  Correct Answer: B

  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