Lattice-Based and Post-Quantum Cryptography ECES Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   In lattice-based cryptography, what is the Shortest Vector Problem (SVP)?

   • AFinding the closest lattice point to a given target point
   • BFinding the shortest nonzero vector in a given lattice
   • CFinding a basis of a lattice with the shortest possible vectors
   • DFinding a vector that is orthogonal to all lattice vectors
   Reveal Solution Discussion Select an answer first
2. 7foundation · easy

   What is the role of the error vector e in LWE-based encryption?

   • AIt introduces noise that makes the problem hard to solve
   • BIt is used to encrypt the message directly
   • CIt is the private key used for decryption
   • DIt is a public parameter shared by all users
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4. 8application · medium

   A security architect is planning a migration to post-quantum cryptography for a large enterprise. The organization currently uses RSA-2048 for digital signatures and ECDH for key exchange. The architect wants to minimize the risk of a 'harvest now, decrypt later' attack while ensuring that the new algorithms are standardized and widely vetted. Which approach best addresses the immediate threat while maintaining compatibility with existing systems?

   • ASwitch to SPHINCS+ for key exchange and Falcon for signatures, as both are NIST-selected and provide strong security.
   • BReplace RSA and ECDH with Kyber for key exchange and Dilithium for signatures immediately, removing all classical algorithms.
   • CDeploy a hybrid scheme that combines ECDH with Kyber for key exchange and RSA with Dilithium for signatures, keeping both classical and post-quantum algorithms active.
   • DContinue using RSA-2048 and ECDH but increase key sizes to 4096 bits and 512 bits respectively to resist quantum attacks.
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5. 9foundation · easy

   What is the fundamental security property that hash-based signatures rely on?

   • AThe hardness of the shortest vector problem
   • BThe collision resistance and preimage resistance of hash functions
   • CThe difficulty of factoring large integers
   • DThe hardness of the discrete logarithm problem
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6. 10application · medium

   A security architect is evaluating lattice-based encryption for a new messaging platform. The architect wants to ensure that decryption is efficient on low-power mobile devices while maintaining security against quantum attacks. Which approach best meets this requirement?

   • AUse hash-based signatures for encryption
   • BUse plain LWE with large matrices to maximize security
   • CUse McEliece with Goppa codes for smaller public keys
   • DUse Ring-LWE with polynomial multiplication for smaller keys and faster operations
   Reveal Solution Discussion Select an answer first