A blockchain developer is evaluating post-quantum signature schemes for a new cryptocurrency. The network has very limited block space and needs to minimize transaction size. Which type of post-quantum signature scheme is most appropriate?

Lattice-based signatures like Dilithium, which have relatively small public keys and signatures.

Multivariate-quadratic signatures, which are fast but have very large public keys.

Code-based signatures like those based on McEliece, which have very large public keys.

Hash-based signatures like SPHINCS+, which have very large signatures.

Which innovation is being explored to future-proof blockchain against quantum threats?

Creating a centralized authority to manage all blockchain keys.

Using quantum computers to increase the hash rate of the network.

Increasing the block reward to incentivize quantum miners.

Implementing quantum-resistant signature schemes and quantum key distribution for secure communication.

A blockchain architect is designing a quantum-resistant upgrade for an existing network. The network currently uses ECDSA for signatures and SHA-256 for hashing. The upgrade must be backward-compatible and minimize disruption. Which of the following are valid strategies? (Select all that apply.)

Implement a mechanism to hide public keys until they are used in a transaction.

Require all users to migrate to new keys immediately.

Replace the hash function with a quantum-resistant hash function.

Introduce a new transaction version that uses a post-quantum signature scheme, while keeping the old version valid.

Use a hybrid signature that combines ECDSA and a post-quantum scheme.

Why is it important for a quantum-resistant blockchain to use a post-quantum signature scheme for transaction validation?

To speed up transaction processing by using simpler mathematical operations.

To enable smart contracts to run on quantum computers.

To prevent an attacker with a quantum computer from forging transactions by deriving private keys from public keys.

To reduce the storage required for the blockchain ledger.

Which of the following is an example of a post-quantum cryptographic family?

Elliptic curve cryptography (ECC)

EC-CouncilBlockchain Developer Certification

Domain 9Objective 6

Quantum Computing and Blockchain BDC Practice Questions (Page 6)

Part of the Advanced Concepts and Future Innovations domain, which makes up ~12% of our current practice bank.

40questions here

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Questions 26–30

26application · medium
A blockchain developer is evaluating post-quantum signature schemes for a new cryptocurrency. The network has very limited block space and needs to minimize transaction size. Which type of post-quantum signature scheme is most appropriate?
Select an answer first
27foundation · easy
Which innovation is being explored to future-proof blockchain against quantum threats?
Select an answer first
28expert · hard · select all that apply
A blockchain architect is designing a quantum-resistant upgrade for an existing network. The network currently uses ECDSA for signatures and SHA-256 for hashing. The upgrade must be backward-compatible and minimize disruption. Which of the following are valid strategies? (Select all that apply.)
Select an answer first
29foundation · easy
Why is it important for a quantum-resistant blockchain to use a post-quantum signature scheme for transaction validation?
Select an answer first
30foundation · easy
Which of the following is an example of a post-quantum cryptographic family?
Select an answer first

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