BlockChain Interview Questions and Answers Set 6

51. What is a public key?

A public key is used in the cryptographic algorithm that allows peers in a blockchain to receive funds in his wallet. The public key is attached to a private key creating a pair of keys. Both the pair of the private-public key is used to ensure that the security of the blockchain is ensured. A public key is an alphanumeric string that is unique to a particular node or address.

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

There is no restriction on keeping records of any type in the Blockchain approach. Industries are using Blockchain for securing all types of records.
The common types of records (to name a few) that can be kept on the Blockchains are:
• Records of medical transactions
• Identity management
• Transaction processing
• Business transactions,
• Management activities
• Documentation

53. What is a private key?

A private key is an alphanumeric phrase that is used in pair with a public key to provide encryption and decryption. It is part of cryptographic algorithms that are used in blockchain security. The key is assigned to the key generator and should stay with him only. If he fails to do so, anyone can access the details or data located within the wallet or the address for which the private key is assigned.

54. What is the difference between ethereum and bitcoin blockchain?

A blockchain is a distributed peer-to-peer network. It offers peers to record immutable data and transparency. The difference between bitcoin and ethereum is their approach. Ethereum, being the 2nd generation blockchain solution improves on bitcoin in almost every possible way. The main difference is how they are trying to solve the industry problem. Conceptually, bitcoin is a digital currency whereas ethereum is about smart contracts. Ethereum is also energy efficient as it uses Proof-of-Stake(PoS) consensus algorithm compared to bitcoin’s Proof-of-Work(PoW). This also makes ethereum more scalable compared to bitcoin.

55. Explain the components of a blockchain ecosystem?

Blockchain ecosystem has four main components. They are as follows.

Node application
Shared ledger
Consensus algorithm
Virtual Machine
Each plays a crucial role in ensuring that the blockchain ecosystem works as intended.

Blockchain Technology StackNote: This is one of the most important questions on blockchain technology. We suggest reading more about the blockchain ecosystem, as the interview can easily ask to follow up questions depending on the answer you give.

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56. What are Block Identifiers?

In Blockchain, blocks can be identified by the block header hash and the block height.

57. What are the different types of blockchain technology/ledger?

There are many different types of blockchain technology(ledger). The first type of ledger that we know from bitcoin is the public blockchain. They are truly decentralized in nature. Other types of blockchain/ledger are listed below.

Public blockchain
Private blockchain
Consortium or Federated blockchain

58. Is the blockchain totally different from banking ledger?

Banking ledgers are used to ensure that the transactions can take place correctly. That’s why they trace and timestamp transactions. The significant difference between a banking ledger and a blockchain is how they are governed. The blockchain is decentralized in nature; however, banking ledgers are completely centralized as banks govern them. The blockchain is completely transparent and trustworthy when compared to bank ledgers. Banks are keen on blockchain technology as they can automate most of their banking functionalities, and also provide a trustworthy approach. However, are more likely to use federated blockchain or private blockchain to ensure that they still have control over their operations.

Note: This question is also common in blockchain exam questions if you are appearing in a written format.

59. What are the key features/properties of blockchain?

Key Blockchain Features
There are many key features of blockchain. They include the following.

Blockchain as a data structure: Blockchain can act as a data structure and store different types of data including identity information, insurance, medical and so on.
Immutability: The data once stored in blockchain is immutable. This gives the blockchain tamper detection property as well.

Data protection: As the owner of the data is the source peer itself, data protection is completely dependent on the source. The absence of third-party actors also means that it is secure and offers best data protection
Decentralized ledger technology: The decentralized ledger technology is the most important feature of a blockchain. It can be used by a private organization or public in a variety of use-cases.

Better user anonymity: Users are relatively hidden compared to other traditional networks.
Double spending: Blockchain solves double spending problems using consensus algorithms and distributed ledger technology.

Note: This question is also common in blockchain exam questions if you are appearing in a written format.

60. What is Double Spending? Is it possible to double spend in a Blockchain system?

It’s a condition when one digital token is spent multiple times because the token generally consists of a digital file that can easily be cloned. It simply leads to inflation and organizations must bear a huge loss. One of the primary aims of Blockchain technology is to eliminate this approach up to the possible extent.
Blockchain prevents double spending by confirming a transaction by multiple parties before the actual transaction is written to the ledger. It’s no exaggeration to say that the entirety of bitcoin’s system of Blockchain, mining, proof of work, difficulty etc, exist to produce this history of transactions that is computationally impractical to modify.