Blockchain Interview Questions

Q1. What is a blockchain?

Ans: Blockchain is a technology helps in peer to peer transfer of digital information and assets without any middleman or intermediaries. Blockchain relied on immutable records of the distributed

Q2. What is the basic structure of blockchain?

Ans: Transaction is the basic structure of blockchain. Later, the same transaction is validated and broadcast in an immutable ledger.Many transactions form a box and many boxesform a chain through a digital data link.

Q3. What are the types of Blockchain network?

Ans: Blockchain network can be categorized into 3 types :

(1) Public blockchains: This type of network can be accessed by the general public and make transactions.Bitcoin and Ethereum are two popular public blockchains.

(2) Private blockchains: As the name indicates, the only person which are allowed by network administrators able to participated and make transactions.

(3) Consortium blockchains: It is considered as the semi-decentralized network. Here, similar to the private blockchain, also required permission of network administrator but it is controlled by many companies which operate each node on such a network.

Q4What does Blockchain do?

Ans: Blockchain is, quite simply, a digital, decentralized ledger that keeps a record of all transactions that take place across a peer-to-peer network.

Q5. What are the features of Blockchain?

Ans: The key features of blockchain are,

• Distributed Database – Information stored on a blockchain exists as a shared and continually reconciled database.
• Decentralized Systems – Decentralized systems enables users to store their assets in a network that can be accessed over the Internet.
• Distributed Ledger – It provides information of all the digital transactions and the users who have done the digital transactions ever.
• Safer and Secure Ecosystem – Due to its incorruptible digital ledger of economic transactions that can be programmed to record digital transactions provides safer and secure ecosystem.

Q6. Explain the principle of Blockchain Technology?

Ans: Being a decentralized system of logging, Blockchain technology runs on the basic premise of being a system in which the information can be disseminated without a central authority such as banks, as is the case with traditional financial systems.

Q7. What are the different types of records in Blockchain technology?

Ans: There are two different types of records available in Blockchain, they are,

1. Block Records
2. Transactional Records

Q8. What is a Node in Blockchain?

Ans: In Blockchain, Node is a computer connected to the blockchain network using a client that performs the task of validating and relaying transactions) gets a copy of the blockchain, which gets downloaded automatically upon joining the blockchain network.

Q9. What are confirmations on the Blockchain?

Ans: Bitcoin Confirmations. Roughly every ten minutes, a new block is created and added to the blockchain through the mining process. This block verifies and records any new transactions. The transactions are then said to have been confirmed by the Bitcoin network.

Q10. What are the benefits of the distributed ledger?

Ans: As we know Blockchain is a public ledger and it contains the information like all the participants and all the digital transactions that have ever been executed. There are many advantages of public ledger, they are:

Fraud prevention: In Blockchain data is decentralized and ledger data distributed across the multiple nodes. If there is any unauthorized changes to ledger data, Blockchain technology responds very well and prevents it. Ledger data can’t be changed and it prevents any kind of frauds.

Get rid of multiple ledgers: Blockchain distributed ledger technology helps organizations in maintaining all their transaction data into a single ledger, it reduces the complications of having multiple ledgers.

Ownership Assurance: Distributed ledgers can enable new ways of assuring ownership to the digital assets, goods and intellectual property.

Eliminates Mediatory: Blockchain eliminates mediatory and reduces the transaction time for settlements with keep track of everything in ledger in a secured way.

Q11. Which technology should you use? What are the standards?

Ans: Today, clients tell us there are predominantly two technologies emerging as ‘de facto standards’ for building enterprise blockchain applications: IBM Hyperledger Fabric and Ethereum. At ConsenSys, we build applications on the Ethereum blockchain; both the larger public network, and private Ethereum blockchains.

We use the Ethereum blockchain for three main reasons:

• Ethereum is the only decentralised smart contract platform designed to be general purpose and global from the offset
• With Ethereum, you can deploy private chains, public chain decentralized apps (DApps), and consortium chains, both on premise and in the cloud
• Ethereum has the largest developer pool globally, which is advancing the platform rapidly, and also provides enterprises choice in terms of implementation partners

Later in this series we’ll dive further into the differences between Fabric and Ethereum and the distinction between the public Ethereum blockchain and private implementations.

Q12. Explain the principle of Blockchain Technology?

Ans: Being a decentralized system of logging, Blockchain technology runs on the basic premise of being a system in which the information can be disseminated without a central authority such as banks, as is the case with traditional financial systems.

Q13. How do you recognize a block within the Blockchain approach?

Ans: A hash pointer that each block contains within the online ledger, which acts as a joint between the blocks, is the block within the blockchain approach.

Q14. What are the differences between blockchain ledger and a standard one?

Ans: The first and most important of the distinctions is that Blockchain is a highly decentralized digital ledger which is simple to work on but is immutable once an operation is carried out. The chances of error in this system are far, far fewer than those in the standard one, which is easy to manipulate. Moreover, while most entries to the standard ledger has to be done manually, blockchain automates it, eliminating the smallest chance of tampering.

Q15. What are the blocks within the Blockchain Technology?

Ans: These are used to store the list of records that is in the Blockchain system. Being successively associated with all other blocks, it comes to represent a series known as Blockchain.

Q16. How do you recognize a block within the Blockchain approach?

Ans: A hash pointer that each block contains within the online ledger, which acts as a joint between the blocks, is the block within the blockchain approach.

Q17. Is it possible to switch the data once it’s written in an exceeding block?

Ans: No. This is the core feature of blockchain, which distinguishes it from any other ledger system. If a company wants to make changes to any data, it needs to remove the information from all the blocks as well. This calls for extreme care and caution while entering data. As mentioned, this approach has enormous implications for financial transactions in the future.

Q18.What are the differences between blockchain ledger and a standard one?

Ans: The first and most important of the distinctions is that Blockchain is a highly decentralized digital ledger which is simple to work on but is immutable once an operation is carried out. The chances of error in this system are far, far fewer than those in the standard one, which is easy to manipulate. Moreover, while most entries to the standard ledger has to be done manually, blockchain automates it, eliminating the smallest chance of tampering.

Q19. What kind of records can be kept in a Blockchain? Is there any restriction on same?

Ans: The types of records that are kept in Blockchain are:

1. Business transactions
2. Documentation
3. Identity management
4. Management activities
5. Transaction process
6. Records of medical transactions
7. In fact, there are no restrictions on keeping records in the blockchain.

Q20. Explain some of the key principles in Blockchain that are helpful in eliminating the security threats

Ans:

1.Auditing

2.Securing applications

3. Securing testing and similar approaches
4. Database security
5. Continuity planning
6. Digital workforce training

Q21. Wha are the many different types of blockchain?

Ans: Blockchain can be one of the following three categories:

1. Public blockchain
2. Private blockchain
3. Consortium blockchain

Q22. Is blockchain a transactional database?

Ans: Blockchain is a diversified database used to store data that works on peer-to-peer network concept rather than transactional database that works on integrity constraint concept.