As someone who knows only the very basics of cryptography - would verifying hashes of a file using SHA-1 and a "weak" hash function like MD5 provide any additional protection over just SHA-1? I.e. how much harder would be it be to create a collision in both SHA-1 and MD5 than in just SHA-1?
My common sense intuition is that it would be a lot harder, but I'm guessing theoretically/mathematically it's only a little bit harder given how easy collisions in MD5 are?
It’s actually not much harder at all, as first noted by Joux, “Multicollisions in iterated hash functions. Application to cascaded constructions”, 2004.
My common sense intuition is that it would be a lot harder, but I'm guessing theoretically/mathematically it's only a little bit harder given how easy collisions in MD5 are?