What is the difference between collision resistance and prototype resistance?

Question

For a hash function, what's the difference between collision protection and prototype protection?

Answer 1

from wikipedia: http://en.wikipedia.org/wiki/Cryptographic_hash_function

The properties

Most cryptographic hash functions are designed to enter a string of any length as input and to obtain a hash value of a fixed length. The cryptographic hash function must withstand all known types of cryptanalytic attacks. At a minimum, it should have the following Properties:

Preventive Resistance Given the hash of h, it is difficult to find any message m such that h = hash (m). This concept is related to the one-way function concept. Functions that do not have this property are vulnerable to attack prototypes.

Resistance to the second opening When entering m _{1 it} should be difficult to find another input m ₂ - where m ₁ ! = M ₂ - such that hash (m ₁ ) = hash (m ₂ ). This property is sometimes called weak collision resistance, and features that lack this property are vulnerable to second-providence attacks.

Resistance to collision . It is difficult to find two different messages m ₁ and m ₂ so that hash (m ₁ ) = hash (m ₂ ). Such a pair is called a cryptographic collision hash. This property is sometimes called strong collision resistance. This requires a hash value of at least twice that is required for resistance to providence, otherwise collisions can be detected by a birthday attack.