Method for determining and cataloguing a digital data file fingerprint. A data file, such as an audio file, is converted into digital format. The file is then sampled using at least one reference value. From the occurrences of the samples in the digital data file being equal to the reference value, a fingerprint is determined. This fingerprint is provided to a digital data file fingerprint database, along with proprietary and other related information. Users may then quickly ascertain the proprietary information from a data file through accessing the database with a fingerprint. Furthermore, users may detect whether or not a data file has been manipulated, such as compressed using modern compression technology, by comparing a fingerprint of the suspect data file with an original fingerprint found in the database.