A checksum is a small-sized datum derived from a block of digital data for the purpose of detecting errors which may have been introduced during its transmission or storage. It is usually applied to an installation file after it is received from the download server. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity.
How would you verify data authenticity then? Would transferring a file through the https protocol and then comparing it's hash confirm that it's genuine, or is there more to it than that?
And how would you hash a big 40+gb zip file, would you have to hash the entire contents of the file and, each file within the zip file?
I couldn't find any good resources on how to hash verify big files.