Yes. It also isn't the "second" sha-1 collision, by any means -- you could already trivially use the prefix and colliding blocks from the shattered example and

Yes. It also isn't the "second" sha-1 collision, by any means -- you could already trivially use the prefix and colliding blocks from the shattered example and append any suffix you want to generate more collisions: https://news.ycombinator.com/item?id=13723892 https://news.ycombinator.com/item?id=13723892 A true second collision wouldn't start with the same 320 bytes. A more interesting one might use fewer bits to achieve the collision.