You might be thinking of a hash. Hashes have a cascading effect where a single bit change in the source file has a "waterfall" effect during the hashing where t

You might be thinking of a hash. Hashes have a cascading effect where a single bit change in the source file has a "waterfall" effect during the hashing where the output is drastically different from the hash of the unmodified input. I don't think this is necessarily the case with all encryption mechanisms.