No, the hash is always the same length, a single character and a 4GB movie will generate a hash of the same length (using the same hash algorithm (md5, sha512,

No, the hash is always the same length, a single character and a 4GB movie will generate a hash of the same length (using the same hash algorithm (md5, sha512, etc). I've casually read about it, I think that is the point of the hash, to take an input of any size or length and represent it as a fixed size. The problem with this is hash collisions, weaknesses found in hash algorithms can make it so attackers could generate files to match another files hash (or password or w/e). I think the idea is that they create a harmful file, then add null characters or w/e so the hash algorithm will generate/assign the two different files the same hash.