Universal Numerical Fingerprint (UNF) is a unique signature of the semantic content of a digital object. It is not simply a checksum of a binary data file. Instead, the UNF algorithm approximates and normalizes the data stored within. A cryptographic hash of that normalized (or canonicalized) representation is then computed. The signature is thus independent of the storage format. E.g., the same data object stored in, say, SPSS and Stata, will have the same UNF.
A universal numeric fingerprint is used to guarantee that a two digital objects (or parts thereof) in different formats represent the same intellectual object (or work). UNFs are formed by generating an approximation of the intellectual content of the object, putting this in a normalized form, and applying a cryptographic hash to produce a unique key. (Altman, et al. 2003)
Universal Numeric Fingerprint (UNF) google