A fundamental result in cryptography is that a digital signature scheme can be constructed from an arbitrary one-way function. A proof of this somewhat surprising statement follows from two results: first, Naor and Yung defined the notion of universal one-way hash functions and showed that the existence of such hash functions implies the existence of secure digital signature schemes. Subsequent...

We study the functions whose composition with Baire class one functions are Baire class one functions. We first prove some characterizations of such functions, then investigate a subclass of such functions which are defined in a natural way.