This document discusses privacy-preserving data mining and cryptography. It explains that separate medical institutions may want to conduct joint research while preserving patient privacy. It also discusses how ultra-large databases hold transaction records and how privacy-preserving protocols are needed to limit information leaks during distributed computations, even from adversarial participants. Finally, it discusses how cryptography can enable functions to be computed securely in a way that preserves individual privacy and reveals only the final results of data mining computations.