Blockchain Interview Questions and Answers
Blockchain technology sometimes also referred to as Distributed Ledger Technology (DLT), makes the transactional history of any digital asset unalterable and transparent through the use of decentralization and cryptographic hashing. It is widely popular because it helps in reducing risks, brings out fraud, and brings in scalability for a myriad of users.
Our list of blockchain interview questions shall help you to gain more insights into this subject and also help you secure a job position in this promising field. You can download these interview questions and answers in a PDF format to read along later.
Most Frequently Asked Blockchain Interview Questions
The blockchain is a decentralized and distributed database for unaltered records. Here are some of the reasons why it is trusted:
- Compatible with almost all business applications as it is open-source.
- Extra focus on security as all transactions happen online.
- Enhanced, traceability, transparency, efficiency, and speed.
Note: Due to its unprecedented standards of security, Microsoft has been working on a Blockchain project to create Digital IDs for more than 1 billion people who currently have no ID to prove their identity. Our Blockchain interview questions shall answer your queries regarding the security methods used by Blockchain.
| Bitcoin | Ethereum |
|---|---|
| This does not allow scripting. | This allows scripting via smart contracts. |
| It is a decentralized cryptocurrency which tracks the ownership of currency in a peer to peer network. | It is a decentralized platform used as a cryptocurrency while focusing on running the program code of any decentralized application. |
A Merkle Tree is also known as Binary Hash Tree. It is a data structure used in Blockchain and cryptocurrencies to encode the Blockchain data more efficiently and securely.
Here are the benefits of using Blockchain Technology:
- It allows users verification without any dependency on third-party software.
- The data structure used in Blockchain is append-only. Hence it cannot be edited or altered with.
- It uses cryptography technology to secure data ledgers.
Note: Although Blockchain is being used by only 0.5% of the world’s population, tech giants like IBM and Microsoft are investing a lot of resources and manpower in Blockchain-related projects. Read our comprehensive collection of blockchain interview questions to know more.
Currently, there are four types of Blockchain:
- Public Blockchain
- Private Blockchain
- Consortium Blockchain
- Hybrid Blockchain
NOTE: If you want to read more about Blockchain then you can visit here.
Blockchain is secure as all the transactions are secured using cryptography. Each transaction is signed using a private key which can be further divided into public keys. If the transaction data has any changes, the signature becomes invalid and the whole block shall be ignored.
A trapdoor function is one that is easy to compute within one direction. It is very tough to compute the other way unless you have special information/privileges. It is used in Blockchain development for public-key encryption, representing ideas of addresses and private keys.
Blockchain uses encryption(cryptography) to protect the identities of any network, ensure secure transactions, and protect valuable information. A combination of public and private keys enables the encryption of the information.
scriptPubKey is technically a locking script which is placed on the output of any Bitcoin-based transactions requiring special conditions to be met for the user to spend his/her Bitcoins.
Double Spending is a phenomenon that occurs when a Blockchain network is disrupted and cryptocurrencies are stolen. This is a possibility in a Blockchain system.