BLOCKCHAIN INTERVIEW
QUESTIONS WITH CORRECT
ANSWERS!!
What is the difference between Blockchain and Hyperledger? - ANSWERBlockchain
is a decentralized technology of immutable records called blocks, which are secured
using cryptography. Hyperledger is a platform or an organization that allows people
to build private Blockchain.
Blockchain is divided into public, private, and consortium Blockchains and
Hyperledger is a private Blockchain technology with access to Blockchain data and
is limited to predefined users, configurations, and programming.
Wherever we talk about public Blockchain, it refers to the usage of Blockchain on the
internet, and Hyperledger-based Blockchain solutions are solutions meant for usage
on the intranet, within an organization.
How do you explain Blockchain technology to someone who doesn't know it? -
ANSWERBlockchain technology is a distributed ledger, which stores transaction
details in the form of immutable records or non-modifiable records (called blocks)
which are secured using cryptography.
There are a previous hash, transaction details, nonce, and target hash value. A block
is like a record of the transaction. Each time a block is verified, it gets recorded in
chronological order in the main Blockchain. Once the data is recorded, it cannot be
modified.
How is Blockchain distributed ledger different from a traditional ledger? - ANSWERA
Blockchain distributed ledger is highly transparent as compared to a traditional
ledger.
Blockchain distributed ledgers are irreversible. Information registered on a distributed
ledger cannot be modified whereas on a traditional ledger it is reversible.
A distributed ledger is more secure. It uses cryptography and every transaction is
hashed and recorded whereas in traditional ledger security can be compromised.
In a distributed ledger, there is no central authority. It is a distributed system and the
participants hold the authority to maintain the sanity of the network and are
responsible for validating the transactions. Traditional ledgers are based on the
concept of centralized control, which controls all transactions.
, In a distributed ledger, identities are unknown and hidden whereas in traditional
ledger identities of all participants have to be known before the transactions happen.
In a distributed ledger, there is no single point of failure as the data is distributed and
information is shared across multiple nodes. If one node fails, the other nodes carry
the same copy of the information. In comparison, traditional ledgers have a single
point of failure. If a single system crashes, the entire network comes to a standstill.
In a distributed ledger, data modification or change cannot be done but for a
traditional ledger, it is possible.
In a distributed ledger, validation is done by the participants in the network while in a
traditional ledger, validation is done by a centralized authority.
The copy of the ledger is shared amongst participants in a distributed ledger while in
a traditional ledger, a single copy is maintained in a centralized location. It is not
shared amongst the participants.
How do you identify a block? - ANSWEREvery block consists of four fields -
The hash value of the previous block (thereby getting linked in a blockchain)
It contains details of several transaction data
It has a value called the nonce. The nonce is a random value which is used to vary
the value of the hash in order to generate hash value less than the target
Hash of the block itself. It is the digital signature of the block and an alphanumeric
value used to identify a block
The hash address is the unique identification of the block. It is a hex value of 64
characters that have both letters and digits. It is obtained by using the SHA - 256
algorithms.
The hash of the previous block, transaction data, and the nonce consolidate the
header of the block. They are together passed through a hashing function and then
the hash value is generated.
What is cryptography? What is its role in Blockchain? - ANSWERBlockchain uses
cryptography to secure users' identities and ensure transactions are done safely with
a hash function.
Cryptography uses public and private keys in order to encrypt and decrypt data. In
the Blockchain network, a public key can be shared with all the Bitcoin users but a
private key (just like a password) is kept secret with the users.
Bitcoin uses SHA - 256 which is secure and provides a unique hash output for every
input. The basic feature of this algorithm is whatever input you pass, it will give you a
standard alphanumeric output of 64 characters. It is a one-way function from which
you can derive an encrypted value from the input, but not vice-versa.
QUESTIONS WITH CORRECT
ANSWERS!!
What is the difference between Blockchain and Hyperledger? - ANSWERBlockchain
is a decentralized technology of immutable records called blocks, which are secured
using cryptography. Hyperledger is a platform or an organization that allows people
to build private Blockchain.
Blockchain is divided into public, private, and consortium Blockchains and
Hyperledger is a private Blockchain technology with access to Blockchain data and
is limited to predefined users, configurations, and programming.
Wherever we talk about public Blockchain, it refers to the usage of Blockchain on the
internet, and Hyperledger-based Blockchain solutions are solutions meant for usage
on the intranet, within an organization.
How do you explain Blockchain technology to someone who doesn't know it? -
ANSWERBlockchain technology is a distributed ledger, which stores transaction
details in the form of immutable records or non-modifiable records (called blocks)
which are secured using cryptography.
There are a previous hash, transaction details, nonce, and target hash value. A block
is like a record of the transaction. Each time a block is verified, it gets recorded in
chronological order in the main Blockchain. Once the data is recorded, it cannot be
modified.
How is Blockchain distributed ledger different from a traditional ledger? - ANSWERA
Blockchain distributed ledger is highly transparent as compared to a traditional
ledger.
Blockchain distributed ledgers are irreversible. Information registered on a distributed
ledger cannot be modified whereas on a traditional ledger it is reversible.
A distributed ledger is more secure. It uses cryptography and every transaction is
hashed and recorded whereas in traditional ledger security can be compromised.
In a distributed ledger, there is no central authority. It is a distributed system and the
participants hold the authority to maintain the sanity of the network and are
responsible for validating the transactions. Traditional ledgers are based on the
concept of centralized control, which controls all transactions.
, In a distributed ledger, identities are unknown and hidden whereas in traditional
ledger identities of all participants have to be known before the transactions happen.
In a distributed ledger, there is no single point of failure as the data is distributed and
information is shared across multiple nodes. If one node fails, the other nodes carry
the same copy of the information. In comparison, traditional ledgers have a single
point of failure. If a single system crashes, the entire network comes to a standstill.
In a distributed ledger, data modification or change cannot be done but for a
traditional ledger, it is possible.
In a distributed ledger, validation is done by the participants in the network while in a
traditional ledger, validation is done by a centralized authority.
The copy of the ledger is shared amongst participants in a distributed ledger while in
a traditional ledger, a single copy is maintained in a centralized location. It is not
shared amongst the participants.
How do you identify a block? - ANSWEREvery block consists of four fields -
The hash value of the previous block (thereby getting linked in a blockchain)
It contains details of several transaction data
It has a value called the nonce. The nonce is a random value which is used to vary
the value of the hash in order to generate hash value less than the target
Hash of the block itself. It is the digital signature of the block and an alphanumeric
value used to identify a block
The hash address is the unique identification of the block. It is a hex value of 64
characters that have both letters and digits. It is obtained by using the SHA - 256
algorithms.
The hash of the previous block, transaction data, and the nonce consolidate the
header of the block. They are together passed through a hashing function and then
the hash value is generated.
What is cryptography? What is its role in Blockchain? - ANSWERBlockchain uses
cryptography to secure users' identities and ensure transactions are done safely with
a hash function.
Cryptography uses public and private keys in order to encrypt and decrypt data. In
the Blockchain network, a public key can be shared with all the Bitcoin users but a
private key (just like a password) is kept secret with the users.
Bitcoin uses SHA - 256 which is secure and provides a unique hash output for every
input. The basic feature of this algorithm is whatever input you pass, it will give you a
standard alphanumeric output of 64 characters. It is a one-way function from which
you can derive an encrypted value from the input, but not vice-versa.
