Best Choice For Hashing Filename of Previously Uploaded File

So I'm in the midst of reformatting the file storage structure for a project, and through a variety of means I'm trying to condense the number of semi-repeated folders (as in rather than 5 folders for different parts of a model, they'll all go into one folder). But my biggest concern is any possible form of overwrite (the previous naming functions make me cringe) so I am trying to find out if it is possible, at all, to get a hashname (or something like it) for a file that has been previously uploaded to the Laravel project just to make it easier for me to feel a bit better about overwrites and ensure that previous files don't accidentally overwrite themselves because of the poor naming structure...

Any suggestions are welcome and I'd be incredibly grateful for any help. Thanks!