The two PDF files shared as proof of the attack can be considered weapons: > [...] SHA-1 colliding files are currently breaking SVN repositories [https://bugs.webkit.org/show_bug.cgi?id=168774#c23%3CPaste%3E]. Subversion servers use SHA-1 for deduplication and repositories become corrupted when two colliding files are committed

Matt Green: > In crypto we have the idea that hash function collisions should be really hard to find, even if they're 'useless'. [...] [A real-world collision attack] is the equivalent of finding out that your scalpel wasn't sterilized properly. It may not verifiably have germs on it, but the whole instrument