File names based on file content

So, some algorithm for generating a unique, sensible length filename based on the binary content of the file. Two files with the same binary content must have the same name. Obviously there would be limitations for this, since apparently you would not have unique smallest size names for every large set of large files differing only by a small number of bits. But there seems to be some heuristic, best approximation to this, which uses the known attributes of typical image files, for example. If I had the name of some algorithm that does this, I can find it and find other approaches.