A government agency is implementing a long-term document signing system. They need signatures that remain valid for 50 years. They are considering SPHINCS+ and Dilithium. Which factor is most important in their decision?

SPHINCS+ has faster verification, which is important for future systems.

SPHINCS+ relies only on hash function security, which is considered more conservative and likely to remain secure for decades.

Dilithium is based on lattice problems, which are proven to be hard for quantum computers.

Dilithium has smaller signatures, which is more important for long-term storage.

A research team is studying post-quantum cryptography and wants to understand why isogeny-based schemes like SIKE were not selected by NIST. Which reason best explains this?

SIKE was based on hash functions, which are not quantum-resistant

SIKE was too slow for practical use

SIKE was found to be vulnerable to a practical key-recovery attack

SIKE had excessively large key sizes

EC-CouncilCertified Encryption Specialist

Domain 6Objective 2

Lattice-Based and Post-Quantum Cryptography ECES Practice Questions (Page 7)

Part of the Quantum Computing and Cryptography domain, which makes up ~11% of our current practice bank. EC-Council does not publish an official question count, but from its 120-minute exam (~50–80 total, ~6–9 in this domain), expect 3–5 from this objective — we provide 45 practice questions to prepare you well beyond it. (estimate)

45questions here

9free pages

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Questions 31–35

31expert · hard
A government agency is implementing a long-term document signing system. They need signatures that remain valid for 50 years. They are considering SPHINCS+ and Dilithium. Which factor is most important in their decision?
Select an answer first
32foundation · easy
Which NIST-selected algorithm is a hash-based digital signature scheme?
Select an answer first
33application · medium
A research lab is considering code-based cryptography for long-term archival encryption. The lab values a very high security margin and is willing to accept large public keys. Which algorithm best fits this requirement?
Select an answer first
34application · medium
A company needs a post-quantum digital signature scheme that relies solely on the security of hash functions, because the company's compliance team wants to avoid assumptions about the hardness of structured algebraic problems. Which scheme should the company choose?
Select an answer first
35application · medium
A research team is studying post-quantum cryptography and wants to understand why isogeny-based schemes like SIKE were not selected by NIST. Which reason best explains this?
Select an answer first

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Lattice-Based and Post-Quantum Cryptography ECES Practice Questions (Page 7)

Questions 31–35

A government agency is implementing a long-term document signing system. They need signatures that remain valid for 50 years. They are considering SPHINCS+ and Dilithium. Which factor is most important in their decision?

Which NIST-selected algorithm is a hash-based digital signature scheme?

A research lab is considering code-based cryptography for long-term archival encryption. The lab values a very high security margin and is willing to accept large public keys. Which algorithm best fits this requirement?

A company needs a post-quantum digital signature scheme that relies solely on the security of hash functions, because the company's compliance team wants to avoid assumptions about the hardness of structured algebraic problems. Which scheme should the company choose?

A research team is studying post-quantum cryptography and wants to understand why isogeny-based schemes like SIKE were not selected by NIST. Which reason best explains this?

Keep studying — Quantum Computing and Cryptography