Homomorphic Encryption: Secure Computations on Encrypted Data

Question 1

In blockchain technology, what is a key application of homomorphic encryption?

Accepted Answer

Performing computations on encrypted data

Answer

Securely storing sensitive data on the blockchain

Answer

Anonymizing blockchain transactions

Question 2

Which of the following is the defining characteristic of homomorphic encryption?

Accepted Answer

It enables computations to be performed on encrypted data without decrypting it.

Answer

It is solely employed to safeguard the data's integrity within a blockchain.

Answer

It utilizes the principles of zero-knowledge proofs.

Question 3

Which of the following algorithms is commonly utilized for homomorphic encryption?

Accepted Answer

Paillier cryptosystem

Answer

SHA-256

Answer

RSA

Answer

AES-256

Question 4

In the context of blockchain, how does homomorphic encryption contribute to enhanced privacy?

Accepted Answer

It allows smart contracts to execute computations on encrypted user data while maintaining privacy.

Answer

It safeguards the anonymity of users by encrypting their blockchain addresses.

Question 5

Which of the following represents a potential limitation of homomorphic encryption?

Accepted Answer

It can demand substantial computational resources for large datasets.

Answer

It is inherently susceptible to quantum attacks.

Answer

It requires a third-party authority to generate encryption keys.

Question 6

What is the primary function of a 'ciphertext evaluator' in homomorphic encryption?

Accepted Answer

It performs computations on encrypted data without requiring decryption.

Answer

It authenticates the integrity of encrypted data.

Answer

It generates pairs of public and private keys.

Question 7

Which of the following is NOT a key feature of homomorphic encryption?

Accepted Answer

Reveals plaintext to trusted parties

Answer

Preserves data privacy

Answer

Protects data integrity

Answer

Computes on encrypted data

Question 8

Which algorithm is commonly used in fully homomorphic encryption schemes?

Accepted Answer

Cheon-Kim-Kim-Song (CKKS)

Answer

ElGamal

Answer

RSA

Answer

AES

Question 9

What is the primary distinction between homomorphic and conventional encryption?

Accepted Answer

Homomorphic encryption allows mathematical operations on encrypted data

Answer

Homomorphic encryption is inherently more efficient than conventional encryption

Answer

Conventional encryption provides superior security guarantees

Question 10

What is the role of 'ciphertext multiplication' in homomorphic encryption?

Accepted Answer

Enables complex mathematical computations on encrypted data

Answer

Decrypts the encrypted data

Answer

Validates the integrity of the encrypted data

Answer

Encrypts the plaintext data

Question 11

What is the significance of key rotation in homomorphic encryption systems?

Accepted Answer

Preserves ongoing confidentiality and data protection by preventing unauthorized access

Answer

Minimizes storage requirements and optimizes resource utilization

Answer

Enhances computational efficiency and reduces latency

Question 12

What type of operations can be performed on data that is encrypted using homomorphic encryption?

Accepted Answer

Mathematical computations

Answer

Data compression

Answer

Database queries

Answer

Data decryption

Question 13

Which of the following is a widely used homomorphic encryption scheme?

Accepted Answer

Brakerski-Gentry-Naor (BGN)

Answer

RSA

Answer

Advanced Encryption Standard (AES)

Answer

Elliptic Curve Cryptography (ECC)

Question 14

What is the main security benefit of using homomorphic encryption in blockchain applications?

Accepted Answer

Data privacy is preserved during computations.

Answer

Transaction speed is increased.

Answer

Data integrity is enhanced.

Answer

Storage requirements are reduced.

Question 15

Which of these scenarios demonstrates a potential real-world use of homomorphic encryption?

Accepted Answer

Secure multi-party computations in finance or healthcare.

Answer

Cloud storage of personal documents.

Answer

Data mining on social media platforms.

Question 16

Which of the following is NOT a characteristic of homomorphic encryption?

Accepted Answer

Allows decryption without the private key.

Answer

Enables computations on encrypted data.

Answer

Preserves data privacy.

Answer

Supports both addition and multiplication operations.

Question 17

What type of homomorphic encryption allows only a limited set of operations on encrypted data?

Accepted Answer

Partially Homomorphic Encryption

Answer

Fully Homomorphic Encryption

Answer

Somewhat Homomorphic Encryption

Answer

Additive Homomorphic Encryption

Question 18

In a blockchain-based medical records system, how can homomorphic encryption improve patient privacy?

Accepted Answer

Allowing authorized healthcare providers to analyze medical data without decrypting it.

Answer

By eliminating the need for encryption altogether.

Answer

By ensuring that only the patient can access their own medical records.

Question 19

Which of the following algorithms is an example of a Fully Homomorphic Encryption scheme?

Accepted Answer

Brakerski-Gentry Scheme

Answer

Paillier Cryptosystem

Answer

RSA Cryptosystem

Answer

ElGamal Cryptosystem

Question 20

How does homomorphic encryption contribute to enhanced privacy in blockchain applications?

Accepted Answer

By allowing transactions and data to be processed without revealing the underlying information.

Answer

By enabling faster transaction processing speeds.

Answer

By reducing the need for intermediaries in transactions.

Question 21

In a decentralized finance (DeFi) protocol, how can homomorphic encryption be used to protect user data?

Accepted Answer

By allowing smart contracts to perform computations on encrypted financial data without compromising privacy.

Answer

By encrypting the entire blockchain.

Question 22

What is the main advantage of using a Fully Homomorphic Encryption scheme over a Partially Homomorphic Encryption scheme?

Accepted Answer

It supports an unlimited number of computations on encrypted data.

Answer

It is more secure against attacks.

Answer

It is faster and more efficient.

Question 23

In a scenario where a government agency wants to analyze anonymized census data while preserving individual privacy, which cryptographic technique is most suitable?

Accepted Answer

Homomorphic Encryption

Answer

Symmetric Encryption

Answer

Asymmetric Encryption

Question 24

What is the primary function of a bootstrapping operation in homomorphic encryption?

Accepted Answer

To reduce the noise accumulated during computations on encrypted data.

Answer

To generate new encryption keys.

Answer

To enhance the security of the encryption scheme.