3.5 Identify and Describe Quantum Security Risks (e.g., Harvest Now, Decrypt Later Attacks) and Palo Alto Networks Platform Capabilities to Address Them (e.g., Post-Quantum Readiness, Hybrid Cryptography) NETWORK-SECURITY-PROFESSIONAL Practice Questions (Page 4)

Questions 16–20

1. 16application · medium

   A software company is designing a new authentication system. They want to use a digital signature algorithm that will remain secure against quantum attacks. Which algorithm should they choose?

   • AHMAC-SHA256, a keyed-hash message authentication code
   • BRSA-3072, a classical algorithm with a larger key size for increased security
   • CCRYSTALS-Dilithium, a lattice-based digital signature algorithm selected by NIST for post-quantum security
   • DECDSA with P-521 curve, an elliptic curve algorithm with a large key size
   Reveal Solution Discussion Select an answer first
2. 17foundation · medium

   Why does a quantum computer's ability to factor large numbers efficiently undermine the security of RSA encryption?

   • ARSA relies on the practical difficulty of factoring the product of two large primes, which quantum algorithms can solve much faster.
   • BRSA uses symmetric keys that are too short for quantum computers to handle.
   • CRSA keys are generated using quantum random number generators, which are insecure.
   • DRSA encryption is based on the discrete logarithm problem, which quantum computers can solve by brute force.
   Reveal Solution Discussion Select an answer first
4. 18foundation · medium

   Why do harvest now, decrypt later attacks pose a long-term data confidentiality risk?

   • AThe attack requires continuous decryption of data in real time, which is impossible with current technology.
   • BHarvest now, decrypt later attacks rely on breaking encryption keys that are reused across multiple systems.
   • CQuantum computers can decrypt data from the past by exploiting time-travel paradoxes.
   • DEncrypted data captured today can be stored and decrypted in the future when quantum computers become powerful enough to break the encryption.
   Reveal Solution Discussion Select an answer first
5. 19foundation · medium

   Why are elliptic curve cryptography (ECC) algorithms like ECDSA and ECDH considered vulnerable to quantum attacks?

   • AThey rely on the discrete logarithm problem, which Shor's algorithm can solve efficiently.
   • BThey rely on hash functions that can be inverted by quantum computers.
   • CThey are symmetric algorithms that are vulnerable to Grover's algorithm.
   • DThey use small key sizes that can be brute-forced by quantum computers.
   Reveal Solution Discussion Select an answer first
6. 20application · medium

   A security analyst is reviewing the cryptographic algorithms used in their organization's PKI. They want to identify which algorithms are vulnerable to quantum attacks. Which of the following algorithms is most vulnerable?

   • ASHA-256, which relies on the difficulty of finding preimages
   • BRSA-2048, which relies on the difficulty of factoring large prime numbers
   • CAES-256, which relies on substitution-permutation networks
   • DHMAC-SHA256, which relies on a secret key and a hash function
   Reveal Solution Discussion Select an answer first