Explain types of Resistance any Cryptographic Hash Function shall have?

Technology CommunityCategory: Hash TablesExplain types of Resistance any Cryptographic Hash Function shall have?
VietMX Staff asked 3 years ago

In cryptography, hash functions provide three separate functions.

  1. Collision resistance: How hard is it for someone to find two messages (any two messages) that hash the same.
  2. Preimage Resistance: Given a hash, how hard is it to find another message that hashes the same? Also known as a one way hash function.
  3. Second preimage resistance: Given a message, find another message that hashes the same.

These properties are related but independent. For example, collision resistance implies second preimage resistance, but not the other way around. For any given application, you will have different requirements, needing one or more of these properties. A hash function for securing passwords on a server will usually only require preimage resistance, while message digests require all three.