In addition to his research, Garfinkel is a journalist, an entrepreneur and an inventor; his work is generally concerned with computer security, privacy and information technology.

[5] During the summer of 1987, he worked at Brown University's IRIS Project, where he developed a server allowing CDROMs to be shared over a network simultaneously by multiple workstations.

[6] In 1991, while a senior editor at NeXTWORLD magazine, Garfinkel created an address book program for the NeXT Computer called SBook.

In 2003, Garfinkel and Abhi Shelat published an article[12] in IEEE Security & Privacy magazine reporting on an experiment in which they purchased 158 used hard drives from a variety of sources and checked to see whether they still contained readable data.

In 2006, Garfinkel introduced cross-drive analysis, an unsupervised machine learning algorithm for automatically reconstructing social networks from hard drives and other kinds of data-carrying devices that are likely to contain pseudo-unique information.

[13] In September 2006, Garfinkel joined the faculty of the Naval Postgraduate School (NPS) in Monterey, California, as an associate professor of Computer Science.