Almost a decade ago Raymond Chen blogged about the "hash reset attack" cautioning developers to record the content length in addition to the message digest.
Recently I came up with a variation on the MD5 hashing algorithm that incorporates the file size. I've called this algorithm 'MDS' for 'Message Digest + Size' but hilariously "MDS" is a "cancer"... :P
You can see the JavaScript or PHP implementation of MDS here.
So, is this a good idea? Do you think it would raise the bar for collision generation? I'm way out of my depth... sort of seems like a good idea, but I'm not armed with facts.
Perhaps, as I have been cautioned, I shouldn't be using MD5 at all..?