Basically what I'm looking for is the most efficient (fast & secure) way to check a version or the hash of a file. I currently use MD5, but it takes a while to check the hash of a 800mb file.
Any suggestions?
EDIT: By secure, I mean like the users can not edit it.
I'm not sure if users can edit hashes, but they can edit other files that simply contains the version number and such.
EDIT 2: Why the random down voting? What did I do?