The difference between a decentralized and a distributed system is?

A decentralized system is not wholly owned by a single entity

A decentralized system is hosted across multiple datacenters

Distributed and decentralized are the same thing

A decentralized system is not wholly owned by a single entity

A distributed system is not wholly owned by a single entity

If a Proof of Work blockchain such a s Bitcoin or Ethereum changed to a Proof of Stake consensus paradigm, which key component of the Proof of Work process would be eliminated?

There would be no need for the miners or nodes to perform a guessing game

The need to solve Byzantine Fault Tolerance

All fees related to transactions would be removed

The blockchain network would no longer have to display public transactions

Which factor influences the gas cost to deploy a Smart Contact on the Ethereum blockchain?

The total size of the complied Smart Contract measured in kilobytes

None. Smart Contract deployment has a fixed gas cost

The types of operations written in code within the Smart Contract

The current Ethereum market conditions

The total size of the complied Smart Contract measured in kilobytes

How does a client app communicate with Hyperledger fabric chaincode (Smart Contracts)?

The app uses an SDK which invokes functionality on the chaincode which then announces the transaction to any peers required to endorse the transaction

The app uses Hyperledger Composer to communicate with CouchDB which in turn invokes chaincode functionality

Client apps don't communicate with Hyperledger fabric directly, they must use Hyperledger Composer for the transmission

The app points to a node's IP address, then calls an invoke function on the chaincode address to start the write process

On the Ethereum blockchain the "nonce" of a transaction:

Is used to ensure that transactions by a given account are written in sequential order

Holds the gas amount to be paid to the miner writing the block that contains the transaction

Is used to ensure that transactions by a given account are written in sequential order

Is reset to zero after each successfully mined blocked

Must always start with four zeroes

To interact with a deployed Ethereum Smart Contract, a user or app must:

Have a reference to the public address of the deployed Smart Contract

Have the appropriate permissions needed to invoke the functions of the Smart Contract

Have sufficient gas to perform read and write operations against the Smart Contract

One critical business consideration you must account for when choosing Hyperledger Fabric over Ethereum is:

Who you will have host the nodes and how will you deploy the network

If your blockchain will use Proof of Work or Proof of Stake

Which cryptographic algorithms Hyperledger Fabric employs

How you will implement your own gas/fee system

Which of these demonstrates the correct order of the lifecycle of a transaction on Ethereum blockchain?

1. User uses Dapp/web3 to start transaction

User signs the transaction with their private key

Transaction validated on locally running node

Transaction broadcast to entire network

Miners choose to accept or pass on the transaction

Miner takes each accepted transaction and writes it to the current block

1. User uses Dapp/web3 to start transaction

Transaction broadcast to entire network

If accepted by the network, user signs transaction with private key

Miners choose to accept or pass on the transaction

Which of the following is true concerning Hyperledger Composer?

It's a toolset and framework for easily developing business networks

It's a competing blockchain to Hyperledger Fabric in the Hyperledger suite of tools

It's an API layer that sits above Hyperledger Fabric and is required to interact with the Fabric blockchain

It's a toolset and framework for easily developing business networks

It's a consensus-focused replicable state machine framework for blockchain development

Which of the following would create a blockchain transaction?

Updating an internal State variable

The "Nothing-at-Stake" problem that could be realized by Proof of Stake networks would be caused by what?

If all of the validator nodes are taken offline

If validator nodes reject all transactions

Validator nodes approving all transactions on old and new software after a hard fork occurs

Proof of Stake based blockchain systems use what design to permit valid write transactions?

Validator nodes each give or pay a stake in order to write transactions, and if malicious, will lose their stake

A genesis "Stake" node approves or disapproves transactions announced from other nodes

Validator nodes each give or pay a stake in order to write transactions, and if malicious, will lose their stake

Stakeholders or early product investors host nodes that approve or disapprove transactions from other nodes

Every node on the network holds an equal stake, and if malicious, gets flagged for removal

Public blockchains can alter the blockchain ledger by:

Re-hashing the blocks from the total block height down to the genesis block

Creating a hard fork of the blockchain data, tooling and/or software

Achieving community consensus via a Smart Contract to update the ledger

Re-hashing the blocks from the total block height down to the genesis block

Blockchain ledgers are immutable and can never be altered

By default, who can see transaction details on a public/open blockchain?

The network owner / administrator

In what way(s) can Ethereum Smart Contract functions be invoked?

Through code executed in other Smart Contracts and through web3.js or any JSON-RPC library

Only through code executed in other Smart Contracts and XML-RPC

Through code executed in other Smart Contracts and through web3.js or any JSON-RPC library

Only through code executed in another Smart Contract

Smart Contracts cannot be externally invoked. They become autonomous at launch and cannot be called.

Which technical feature of blockchain best promotes the notion of a blockchain being "censorship resistant"?

An immutable ledger of transactions

Smart Contracts/transactional code that is executed "on chain"

Consensus systems through Proof of Work and Proof of Stake

Consider the following scenario: Due to consistent inaccuracies and outdated real estate listings, a residential real estate company wants to build a blockchain solution that accurately depicts which homes (assets) are available for purchase across all countries/provinces. All available homes should be publicly viewable by the general consumer audience, but certain details of the home, such as history of maintenance, should only be viewable by licensed real estate professionals. Which architecture would best solve the product need?

Public data hosted on a public blockchain; Privileged data hosted on a private blockchain

Public data hosted on a public blockchain, Privileged data security hoisted on a private database

The entire solution built on a private blockchain with proper permissions for both public and privileged data

Public and privileged data on hybrid blockchain will Proof of Stake consensus

Public data hosted on a public blockchain; Privileged data hosted on a private blockchain

If a company desires to create a unique cryptocurrency and launch a new blockchain network to host it.

They can both create their own cryptocurrency and launch their own blockchain network with any common open source blockchain tool/system

They must use ERC20 standard for the token, clone the Ethereum Virtual Machine, then launch a series of nodes

They must use ERC20 standard for the token and can use any open source blockchain tool/system to launch a series of nodes

They can both create their own cryptocurrency and launch their own blockchain network with any common open source blockchain tool/system

Taking a series of unrelated transactions and writing them to a particular block is:

Highly insecure and considered bad practice

Most common in public blockchain

Most common in permissioned blockchains

Consider the following scenario: A solo app developer wants to create their own cryptocurrency and build a blockchain based that allows users to buy and sell second-hand items with that cryptocurrency from each other. Before the transaction is considered complete, the purchaser must put the funds in an escrow service and the sender must enter the courier tracking number into that same escrow. Time is of the essence and this developer doesn't want to worry about networking of infrastructure. This app must be fully autonomous or "decentralized". Which architecture would best solve the product need?

Ethereum for token creation; Traditional multitier API and database for escrow service; User-facing features built in web technologies then minified unto a String and deployed to an Ethereum Smart Contract

Ethereum for token creation and escrow service; User-facing features built with web technologies and deployed through IPFS

Ethereum for token creation; Traditional multitier API and database for escrow service; User-facing features built in web technologies then minified unto a String and deployed to an Ethereum Smart Contract

Hyperledger Fabric for the escrow service and token creation using chaincode; User-facing features built with Hyperledger Composer

The product cannot be built. Fully decentralized apps are not yet possible for user interface

A private blockchain like Hyperledger would be the right choice for which scenario:

An enterprise that needs to build a scalable, secure, permissioned blockchain application

A network of family members who want to share passwords and other secure information with one another

Developers who want to rapidly prototype public blockchain solutions

A startup that desires to build a token and blockchain application for their users

Consider the following scenario: A large department store chain is being pressured by lawmakers to provide evidence that proves the store's clothing is not produced through child labor. This is no easy task currently due to the store's clothing being transferred between at least 6 different parties in between creation and placement at the storefront. The store chain is considering the use of blockchain to solve their problem. Discretion in the reading and writing of transactions is highly important to the store chain to protect its proprietary interests. Which solution would best solve the product need?

Use a public blockchain that supports assets, then create a new clothing asset for each item created. When the clothing item is transferred to the next party in the process, require that the associated blockchain asset be transferred to thenext party's blockchain account with relevant metadata. The lawmakers can now view the transactions and transfers at any time.

Use a permissioned blockchain to build the technology. Require every party involved in the process to host a node on you network. Create a new clothing asset for each item created. When the clothing item is transferred to the next partyin the process, have the previous party use your web portal to initialize a chaincode Smart Contract to transfer control of the asset. When the next party receives the asset have them use your web portal to initialize a chaincode Smart Contracts to acknowledge receipt of the asset. Provide read-only permissions to the lawmakers so they can receive the evidence they are looking for.

Both options are equally suitable

Which one of the following is true concerning Hyperledger Fabric?

Because it is permissioned, it is impossible to display data to the general public

Cryptocurrency cannot be created or used

because it is permissioned, companies cannot launch products on it

Because it is permissioned, it is impossible to display data to the general public

Which one of the following is a consideration that must be taken into account when using Hyperledger Fabric that you wouldn't need worry about on Ethereum?

How often hard forks occurs on the software

The fees for deploying and using Smart Contracts

How you will provide proper uptime for the network

The level of security of Smart Contracts (chaincode)

How often hard forks occurs on the software

Proof of Stake offers which advantage over Proof of Work?

It is compatible with new generation chipsets

It has a longer history and deeper knowledge base

Which types of data are able to be stored on any given blockchain ledger?

Encrypted textual and numerical data

Each blockchain software specifies its own data storage rules

Any data that is within the UTC-8 standard

Unencrypted textual and numerical data

Encrypted textual and numerical data

In Proof of Work group consensus, the "nonce" refers to?

The random data to be combined with the block data which will produce a hash output matching the current difficulty level

Random nonsense data inserted at the end of a block to fill it completely

The average Bitcoin price over the last 90 days

In common blockchain design, blockchain addresses or "accounts" are generated by:

Creating a hash based on a cryptographic public key and various meta data

A PRNG output guaranteed to be unique

A server/node timestamp added to a PRNG output

Creating a hash based on a cryptographic public key and various meta data

The most recent block height hash combined with a cryptographic private key

Blockchain CBSA Practice Test 5 - Free Online Exam Prep & Questions

Spam

Selling illegal goods, money scams etc.

Hate Speech

Serious attack on a group.

Harassment and bullying

Harassing an individual (including doxing)

Harmful activities

Threatening or glorifying violence or serious harm, including self-harm

Adult content (Consensual)

Nudity/Sexual content

Sexual exploitation and abuse (child safety)

Sexually explicit or suggestive imagery or writing involving minors

Sexual exploitation and abuse (adults and animals)

Sexually explicit or suggestive imagery or writing involving non-consenting adults or non-humans

Plagiarism

Reusing content without attribution (link and blockquotes)

Poorly written

Not in English or has very bad formatting, grammar, and spelling

Inappropriate credential

Author's credential is offensive, spam, or impersonation

Other

Ex. Illegal content, incomplete question...

Blockchain CBSA Practice Test 5

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