Free Practice Questions for Blockchain CBSA Exam

Withdraw funds rather than push funds to them automatically​ Favor pull over push for external calls as we've seen, external calls can fail for a number of reasons, including external errors. To minimize the damage caused by such failures, it is often better to isolate each external call into its own transaction that can be initiated by the recipient of the call. This is especially relevant for payments, where it is better to let users withdraw funds rather than push funds to them automatically. (This also reduces the chance of problems with the gas limit.)

There are several redundant implementations of the Ethereum protocol to ensure the correctness of the implementation. Additionally, not all blockchain nodes operate the same way. Some are purely for developing and hold a blockchain in-memory and just simulate the mining. Real Blockchain Nodes: 1. Cpp-ethereum 2. Go-Etheruem (GETH) 3. Parity In-Memory Blockchain simulations for rapid development: 1. TestRPC 2. Ganache 3. Truffle Developer Console Clients to access the blockchain in a convenient way: 1. MetaMask browser Plugin through Infura 2. Status.IM Android/iOS app through Infura 3. MIST DApp Browser with integrated GETH

Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally.

Secure Registry Services enables Secured Docker Registry of base Hyperledger images and custom images containing chaincodes.

Hyperledger Composer is an open-source application development framework which simplifies the creation of Hyperledger Fabric blockchain applications, thus reducing the time and complexity of development. The tool aims at helping users to create blockchain applications based on Hyperledger Fabric without needing to know the low-level (Go Programming) details involved in blockchain networks.

Truffle is a development environment, testing framework and asset pipeline for Ethereum, aiming to make life as an Ethereum developer easier.

Difficulty and Timestamp block also contains two very important parameters: a difficulty and a timestamp. The difficulty regulates how hard it is to find a block by the miner. The mining time is set to be between 10 and 20 seconds. If it’s beyond 20 seconds, the difficulty is too high and will be automatically lowered going forward. If the mining happens below 10 seconds, then the difficulty increases. The timestamp is the time when a miner found the block. It is not automatically derived, rather it is set by the miner itself and can thus be influenced to a certain degree. The timestamp does not depend on the time zone, as it’s the standard Unix timestamp.

Blockchain 1.0, Grandpa Bitcoin