Traits for Universal Hash Functions.
Universal hash functions select from a "universal family" of possible hash functions selected by a key. They are well suited to the purpose of "one time authenticators" for a sequence of bytestring inputs, as their construction has a number of desirable properties such as pairwise independence as well as amenability to efficient implementations, particularly when implemented using SIMD instructions.
When combined with a cipher, such as in Galois/Counter Mode or the Salsa20 family AEAD constructions, they can provide the core functionality for a Message Authentication Code (MAC).