well i have been reading some more and come across standard deviation and spread. would this be a pursuable possibility? because you could compare that against all other encrypted files (even tho they use a different key) and should be a similar outcome right?
std dev /should/ be moderately comparable from encrypted file to encrypted file of same data, right? or atleast within a certain range. if it is out of this certain range, then you can safely say it is more than likely corrupted right?