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Approximate Matching: Definition and Terminology



Frank Breitinger, Barbara Guttman, Michael McCarrin, Vassil Roussev, Douglas R. White


This document provides a definition of and terminology for approximate matching. Approximate matching is a promising technology designed to identify similarities between two digital artifacts. It is used to find objects that resemble each other or to find objects that are contained in another object. This can be very useful for filtering data for security monitoring, digital forensics, or other applications. The purpose of this document is to provide a definition and terminology to describe approximate matching in order to promote discussion, research, tool development and tool acquisition.
Special Publication (NIST SP) - 800-168
Report Number


Approximate matching, digital forensics, cryptographic hashing


Breitinger, F. , Guttman, B. , McCarrin, M. , Roussev, V. and White, D. (2014), Approximate Matching: Definition and Terminology, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed April 13, 2024)
Created July 1, 2014, Updated October 12, 2021