Privacy-Enhancing Cryptography

One of the major forms of research conducted by criminologists is searching for and analyzing information in published materials. These materials include

peer-reviewed journal articles (articles published in academic journals)
government documents (reports such as those published by the National Institute of Justice [NIJ], FBI, etc.)
mass media reports (articles in major newspapers [The New York Times, The Washington Post, etc.] and electronic media outlets [ABC, Fox, CNN, etc.])

Research paper on Privacy-Enhancing Cryptography (https://csrc.nist.gov/Projects/Cryptographic-Research)

Introduction
The problem
Is there any sub problems?