Advanced Cryptography CAS-005 Practice Questions (Page 6)

Questions 26–28

1. 26foundation · easy

   Which property of quantum computers poses the most direct threat to widely used asymmetric cryptographic algorithms such as RSA and ECC?

   • AThe ability to search unsorted databases in O(sqrt(N)) time
   • BThe ability to clone arbitrary quantum states perfectly
   • CThe ability to factor large integers and compute discrete logarithms exponentially faster
   • DThe ability to break all symmetric encryption regardless of key size
   Reveal Solution Discussion Select an answer first
2. 27application · medium

   A company is deploying a new IoT device that must perform TLS handshakes with a central server. The device has limited CPU power and battery life. The security team wants to ensure the device is protected against future quantum attacks. Which approach is most suitable?

   • AUse a lightweight post-quantum algorithm for key exchange, such as a hash-based or lattice-based scheme, and offload the computation to a hardware accelerator.
   • BUse a symmetric-only protocol with a pre-shared key to avoid public-key cryptography.
   • CUse a larger RSA key (e.g., 4096 bits) to provide more security.
   • DUse RSA-2048 for key exchange and rely on the server to perform the heavy computation.
   Reveal Solution Discussion Select an answer first
3. 28expert · hard

   A cloud provider offers a data analytics service where clients upload encrypted data and the provider performs computations on the encrypted data without ever decrypting it. The provider wants to ensure that the computations are correct and that the client's data remains confidential. Which combination of technologies best supports this requirement?

   • APartially homomorphic encryption (PHE) for all operations and a trusted execution environment (TEE) for key management.
   • BFully homomorphic encryption (FHE) for computations and zero-knowledge proofs for verifiability.
   • CPost-quantum encryption for data at rest and TLS for data in transit.
   • DSymmetric encryption with a shared key and a hardware security module (HSM) for decryption during computation.
   Reveal Solution Discussion Select an answer first