What is a crytographically secure hash function?

Modern cryptography depends on the existence of several special kinds of mathematical functions. One important kind is a one-way function. One-way functions are easy to compute but very hard for anyone to invert. Sometimes we refer to these functions as hash functions and their output as a hash. Cryptographic hash functions are a subset of hash functions that have special properties important to their use in cryptography. Credits: Talking: Geoffrey Challen (Assistant Professor, Computer Science and Engineering, University at Buffalo). Producing: Greg Bunyea (Undergraduate, Computer Science and Engineering, University at Buffalo). Part of the https://www.internet-class.org online internet course. A blue Systems Research Group (https://blue.cse.buffalo.edu) production.