CBE - Certified Blockchain Expert Cryptographic Principles in Blockchain Questions and Answers

Question 1

Which cryptographic principle is primarily responsible for ensuring the integrity and immutability of data within a blockchain by creating a unique, fixed-size output from variable-sized transaction data?

Accepted Answer

Hashing

Answer

Hashing is a one-way cryptographic function that takes an input of any size and produces a fixed-size string of characters, known as a hash. In blockchain, any small change to the input data (like a transaction detail) will result in a completely different hash. This property makes it easy to detect tampering and ensures the integrity of the data stored in each block, linking them together in a secure chain.

Question 2

A user wants to authorize a cryptocurrency transaction on a blockchain network. Which of the following cryptographic tools allows the user to prove ownership of the funds and authorize the transfer without revealing their secret key?

Accepted Answer

Digital Signature

Answer

A digital signature is created using the sender's private key and the transaction data. Others on the network can then use the sender's public key to verify that the signature is authentic and that the transaction has not been altered, thus proving ownership and authorizing the transaction without exposing the private key.

Question 3

In the context of a Bitcoin block, what is the primary purpose of a Merkle Tree?

Accepted Answer

To efficiently and securely verify the integrity of a large set of transactions.

Answer

A Merkle Tree, or hash tree, summarizes all the transactions in a block by repeatedly hashing pairs of transaction hashes until a single hash, the Merkle Root, is left. This structure allows for efficient verification of transactions; a user can check if a transaction is included in a block by only needing the Merkle Root and a small number of hashes (the Merkle proof), rather than downloading and checking every single transaction.

Question 4

Elliptic Curve Cryptography (ECC) is widely used in blockchains like Bitcoin and Ethereum. What is its primary advantage over older algorithms like RSA?

Accepted Answer

It provides the same level of security with smaller key sizes.

Answer

The main advantage of Elliptic Curve Cryptography (ECC) is that it can provide the same level of security as algorithms like RSA but with significantly smaller key sizes. This leads to lower computational overhead, faster operations, and reduced storage and bandwidth requirements, which are crucial for the efficiency and scalability of a blockchain network.

Question 5

A developer is building a new blockchain protocol and needs to select a hashing algorithm. Which of the following is a critical property for the chosen algorithm to prevent attackers from finding two different inputs that produce the same hash output?

Accepted Answer

Collision resistance

Answer

Collision resistance is a crucial property of a cryptographic hash function, meaning it should be computationally infeasible to find two different inputs that produce the exact same hash output. If a hash function is not collision-resistant, an attacker could create a fraudulent transaction that has the same hash as a legitimate one, compromising the integrity of the blockchain.

CBE - Certified Blockchain Expert Practice Test

CBE - Certified Blockchain Expert Practice Test

CBE - Certified Blockchain Expert Cryptographic Principles in Blockchain Questions and Answers