Hashing Algorithms (MD5, SHA, RIPEMD, Tiger, Whirlpool) and HMAC ECES Practice Questions (Page 4)

Questions 16–20

1. 16expert · hard

   A cryptographic module must support a hash function that is structurally distinct from SHA-2 to provide diversity in case of a future SHA-2 weakness. The module already supports SHA-512 and Whirlpool. Which statement best describes the trade-off when choosing Whirlpool over SHA-512?

   • AWhirlpool is faster than SHA-512 on all platforms.
   • BWhirlpool provides a different internal structure (AES-based) but is less widely standardized than SHA-512.
   • CWhirlpool is immune to all known attacks, while SHA-512 is not.
   • DWhirlpool produces a shorter digest than SHA-512, saving storage.
   Reveal Solution Discussion Select an answer first
2. 17application · medium

   A legacy system stores user passwords as unsalted MD5 hashes. The security team is migrating to a more secure scheme but must keep the system operational during the transition. Which approach best addresses the immediate risk while allowing a gradual migration?

   • AKeep MD5 but add a global salt to all new hashes.
   • BSwitch the hashing algorithm to SHA-1 for new passwords and keep MD5 for existing ones.
   • CAdd a per-user salt and rehash all existing passwords with SHA-256 immediately.
   • DForce a password reset for all users and store new passwords with a salted, slow hash like bcrypt or Argon2.
   Reveal Solution Discussion Select an answer first
4. 18application · medium

   A cryptographic library is being updated to include a hash function that is based on the AES design and produces a 512-bit digest. The library already supports SHA-512, but the team wants an alternative that is structurally different from the SHA family. Which algorithm should be added?

   • ARIPEMD-160
   • BTiger
   • CWhirlpool
   • DSHA-3
   Reveal Solution Discussion Select an answer first
5. 19foundation · easy

   What is the output size of the Whirlpool hash function?

   • A128 bits
   • B512 bits
   • C256 bits
   • D160 bits
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6. 20application · medium

   A development team is building an API that needs to authenticate messages between two servers. They currently share a symmetric key, and they want to ensure that any tampering with the message is detected. They are considering using a plain hash of the message with the key prepended. What should the team implement instead?

   • AHMAC with the shared key
   • BA simple checksum of the message
   • CA digital signature with the shared key
   • DEncrypt the message with AES and send the plain hash
   Reveal Solution Discussion Select an answer first