https://hnimn.art/tags/writeup/ Recent content in Writeup on Minh Tran Hugo en-us Sat, 24 Oct 2020 17:00:00 +0700 https://hnimn.art/posts/merklision-merkle-second-preimage/ Sat, 24 Oct 2020 17:00:00 +0700 https://hnimn.art/posts/merklision-merkle-second-preimage/ A SVATTT 2020 qualifier challenge asked for 2020 distinct inputs that all hash to one Merkle root. A second-preimage rewrite gives ten, an odd-length padding bug gives a thousand, and alternating between them gives one answer at every length up to 2048, because each rule's output is the other rule's input.