SHA-1 collider: Make your own colliding PDFs
Is this length extending [1] the already existing Google attack?<p>[1] <a href="https://en.wikipedia.org/wiki/Length_extension_attack" rel="nofollow">https://en.wikipedia.org/wiki/Length_extension_attack</a><p>Edit: yes, looks like it is.<p>As sp332 and JoachimSchipper mentioned, the novelty here is that it contains specially crafted code in order to conditionally display either picture based on previous data (the diff). I can't grok PDF so I still can't find the condition though. Can PDFs reference byte offsets? This is really clever.<p>Edit #2: I misunderstood the original Google attack. This is just an extension of it.