Hashing Algorithms (MD5, SHA, RIPEMD, Tiger, Whirlpool) and HMAC ECES Practice Questions (Page 3)

Questions 11–15

1. 11foundation · easy

   How does RIPEMD-160 compare to SHA-1 in terms of security and design?

   • ARIPEMD-160 is a keyed hash, while SHA-1 is unkeyed.
   • BRIPEMD-160 is faster than SHA-1 on all platforms.
   • CRIPEMD-160 is based on the sponge construction, while SHA-1 uses Merkle–Damgård.
   • DRIPEMD-160 has a larger security margin than SHA-1, though both produce 160-bit digests.
   Reveal Solution Discussion Select an answer first
2. 12application · medium

   A cryptography consultant is reviewing a system that must interoperate with a legacy European payment gateway. The gateway only supports RIPEMD-160 for integrity checks. The consultant must decide whether this is acceptable for a new high-security deployment. What is the most accurate recommendation?

   • AUse RIPEMD-160 only if the data is not sensitive
   • BUse RIPEMD-160 with a longer output by concatenating two passes
   • CUse RIPEMD-160 because it is stronger than SHA-1
   • DNegotiate a change to SHA-256 or another modern algorithm
   Reveal Solution Discussion Select an answer first
4. 13expert · hard

   A forensic analyst is investigating a data breach. The attacker replaced a legitimate file with a malicious one that has the same MD5 hash. The analyst must determine whether this indicates a collision attack or a second preimage attack. What is the key distinction?

   • AIt is impossible to tell without more information
   • BIt is a collision attack because the attacker found two different files with the same hash
   • CIt is a preimage attack because the attacker reversed the hash
   • DIt is a second preimage attack because the attacker matched a specific existing file
   Reveal Solution Discussion Select an answer first
5. 14expert · hard

   A security architect is designing an API authentication scheme. The team wants to use HMAC-SHA256, but a junior engineer suggests using plain SHA-256 of the message with the secret appended. The architect must decide. Which statement best justifies the architect's decision to use HMAC?

   • AHMAC is faster than plain SHA-256.
   • BPlain SHA-256 cannot be used with a secret at all.
   • CPlain SHA-256 with a secret appended is vulnerable to length-extension attacks, while HMAC is not.
   • DHMAC provides confidentiality for the message.
   Reveal Solution Discussion Select an answer first
6. 15foundation · easy

   What does preimage resistance mean for a cryptographic hash function?

   • AIt is infeasible to determine the length of the original message from the hash.
   • BIt is infeasible to find any two messages with the same hash.
   • CGiven a hash value, it is infeasible to find any message that hashes to that value.
   • DGiven a message, it is infeasible to find another message with the same hash.
   Reveal Solution Discussion Select an answer first