Surveillance
Self-Defense

File fingerprint

A sequence of letters and numbers that mathematically represent the contents of a file. Changing the file even a tiny bit will completely change its fingerprint. Checking the fingerprint of a file that you've downloaded, such as a software application or extension, helps to make sure that you got the file that you intended, and that nobody has tampered with it while it was being downloaded.

Synonyms: 

file hash value
JavaScript license information