CBDH Practice Exam Questions with Answers BTA Certified Blockchain Developer – Hyperledger Certification

Blockchain services manages the distributed ledger through a peer to peer protocol that is built on HTTP/2. The optimized data structure provides efficient schemes for maintaining the world state (the state of all transactions on the Blockchain) replicated at many participants.

Hyperledger supports the following two types of transactions. Code deploying transaction: A code deploying transaction submits, updates, or terminates a chaincode. Code invoking transaction: A code invoking transaction is an API call to a chaincode function.

This web-based tool allows developers to learn Hyperledger Composer, model out their business network (domain), test that network, and deploy that network to a live instance of a blockchain network. The playground keeps the development model in browser storage, allowing them to be easily uploaded or downloaded. The playground also allows for CRUD (create, read, update, delete) operations to be performed on asset transactions which are created and logged. Composer playground offers a repository of sample business networks that can provide a base for building your own business network.

SOLO is the Hyperledger Fabric ordering mechanism most typically used by developers experimenting with Hyperledger Fabric networks. SOLO involves a single ordering node and Note Development Only.

Client Node: That initiates the transaction 2. Peer Nodes: Commits Transaction & keeps the data in sync across the ledger 3. Ordered: They are the communication backbones and responsible for the distribution of the transactions

The Infrastructure Module includes the following four modules: Technical, Legal, Marketing, and Organizational.

Nodes use a Peer to Peer protocol not a Client Server. The concept of node is common in all blockchain technologies. The “Node” becomes the communication end point in blockchain technology. Nodes connect to other nodes and that is how a blockchain is formed. Nodes use a type of peer-to-peer protocol for keeping the distributed ledger in sync across the network.

Hyperledger Sawtooth is a modular platform for building, deploying, and running distributed ledgers. Hyperledger Sawtooth includes a novel consensus algorithm, Proof of Elapsed Time (PoET), which targets large distributed validator populations with minimal resource consumption.

Hyperledger business blockchain frameworks reach consensus by performing two separate activities: 1. Ordering of transactions 2. Validating transactions by logically separating these activities, we ensure that any Hyperledger framework can work with any Hyperledger consensus module.

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X509 certificates are used in Hyperledger Fabric. An X.509 certificate is any certificate under the X.509 specification standard for public key infrastructure and Privilege Management Infrastructure (PMI). The X.509 provides standardized formats for: Attribute certificates Public key certificates Certificate revocation lists Certification validation algorithms

Peers are connected to the channel and can receive all the transactions that are broadcasted on that channel. Consensus takes place within a channel by members of the channel only. Channels are membership based.

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Code deploying transaction Code deploying transaction submits, updates or terminates a chaincode. The validating nodes protects the authenticity and integrity of the code and its executing environment. Code invoking transaction Code invoking transaction is an API call to a chaincode function. It is similar to how a URI invokes a servlet in JEE. The displayed function is called upon the instantiation of the chaincode. Each chaincode maintains its own state and a function call is made to trigger chaincode state changes.

Users can use chaincode (for business rules) and membership service (for digital tokens) to design assets, as well as the logic that manages them. There are two popular approaches to defining assets in most blockchain solutions: the stateless UTXO model, where account balances are encoded into past transaction records; and the account model, where account balances are kept in state storage space on the ledger. Each approach carries its own benefits and drawbacks. This blockchain fabric does not advocate either one over the other. Instead, one of our first requirements was to ensure that both approaches can be easily implemented with tools available in the fabric.

It has a modular subsystem design so that different implementations can be plugged in and implemented over time. Modular and extensible means modularity in all components of all frameworks, including: Consensus layer Smart contract layer Communication Layer Data Store Identity services (root of trust, to identify the participants).

Decentralized Autonomous Organization (DAO) can be thought of as a corporation run without any human involvement under the control of an incorruptible set of business rules. A DAO can also be seen as the most complex form of a smart contract, where the bylaws of the decentralized organization are embedded into the code of the smart contract, using complex token governance rules.

Channels ensure privacy in a blockchain network Ordering services may support many channels no just one channel.

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Management is not correct. The Hyperledger Project consists of the following Infrastructure - Ecosystems that accelerate open development and commercial adoption Frameworks – A portfolio of differentiated approaches to business blockchain frameworks developed by a growing community of communities Tools - Typically built for one framework, and through common license and community of communities approach, ported to other frameworks hyperledger.org.

Hyperledger explorer: Hyperledger explorer, which was originally contributed by IBM, Intel, and DTCC, can view, invoke, deploy or query blocks, transactions and associated data, network information (name, status, list of nodes), chain codes and transaction families, as well as other relevant information stored in the ledger.

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To create a network according to an organization's structure, and to bootstrap a channel, we will need to generate the following artifacts: A genesis block, containing organization-specific certificates that serve to initialize the Fabric blockchain. Channel configuration information. Anchor peer configurations for each organization. An anchor peer serves as a fulcrum within an organization, for cross-organization ledger syncing using the Fabric gossip protocol.

Peer nodes commits Transaction & keeps the data in sync across the ledger. They are nodes that maintain the state and copy of a shared ledger. Peers are authenticated by certificates issued by MSP. In Hyperledger Fabric, there are three types of peer nodes depending upon the assigned roles.

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Hyperledger Fabric has a modular component structure and an extensible plug and play framework

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A CouchDB database is closely co-located with a network node and it is embedded within the same operating system process.

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Peer-to-Peer essentially uses data sharing, hosting hardware owned by many not few, fault tolerant, secure, lower performance. It’s common way to share files—a good example was Napster. Peer-to-peer (P2P) file sharing is the distribution of digital media such as software, videos, music, and images through an informal network in order to upload and download files. Typically, P2P software enables users to select which files to share. These files are indexed on a central server, making them available for other users to find and download.

Docker provides a secured, lightweight method to sandbox chaincode execution that is "locked down" Chaincode Services uses Docker to host (deploy) the chaincode without relying on any virtual machine or computer language. Docker provides a secured, lightweight method to sandbox chaincode execution. The environment is a "locked down" and secured container, along with a set of signed base images containing secure OS and chaincode language, runtime and SDK images for Golang Additional programming languages can be enabled

State Based y default, endorsement policies are specified for a channel’s chaincode at instantiation or upgrade time (that is, one endorsement policy covers all of the state associated with a chaincode). However, there are cases where it may be necessary for a particular state (a particular key-value pair, in other words) to have a different endorsement policy. This state-based endorsement allows the default chaincode-level endorsement policies to be overridden by a different policy for the specified keys.

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