Universal one-way hash function

<p>In <a href="/facts/Cryptography/e94PEVau">cryptography</a> a universal one-way hash function (UOWHF, often pronounced "woof") is a type of <a href="/facts/Universal_hashing/NICffew4">universal hash function</a> of particular importance to <a href="/facts/Cryptography/e94PEVau">cryptography</a>. UOWHFs are proposed as an alternative to <a href="/facts/Cryptographic_hash_function/cuxkgbST">collision-resistant hash functions</a> (CRHFs). CRHFs have a strong collision-resistance property: that it is hard, given randomly chosen hash function parameters, to find any collision of the hash function. In contrast, UOWHFs require that it be hard to find a collision where one <a href="/facts/Preimage/KANefMAl">preimage</a> is chosen independently of the hash function parameters.  The primitive was suggested by <a href="/facts/Moni_Naor/I9UuUSTx">Moni Naor</a> and <a href="/facts/Moti_Yung/KrBHvtts">Moti Yung</a> and is also known as "target collision resistant" hash functions; it was employed to construct general digital signature schemes without trapdoor functions, and also within chosen-ciphertext secure public key encryption schemes.
</p><p>The UOWHF family contains a finite number of hash functions with each 
having the same probability of being used.
</p>

Universal one-way hash function open-in-new

Universal one-way hash function