Comment by nextaccountic
3 years ago
In practice the odds can be astronomically low, as in lower than the odds that an asteroid collides with Earth right now and the entire humanity becomes extinct. But only for hashes without known vulnerabilities.
For a vulnerable hash like md5, an attacker can find a collision in a few seconds.
I only say this in case anyone reads your message and gets the wrong idea. Currently, there is no feasible preimage attack for MD5. You can easily generate two colliding inputs, but cannot, given a hash, find an input to generate that hash.
And I don't believe that accidental MD5 collisions are something to worry about.