Say you’re a researcher and you have just made a groundbreaking discovery that solves a massive problem in your field of research. Excited about the discovery, you want to share it with the world at an important conference to be held in six months. What if you don’t trust any third party to escrow your work until then? Will you simply wait and risk someone else beating you to it? You need a way to prove that you reached the solution today, in case someone else publishes the same discovery sometime between today and the day of the conference.

Proofs of sequential work (PoSW) were first introduced in [MMV13]¹. PoSW is a type of protocol that, given a time parameter T (delay), outputs a proof that allows one to prove that s/he performed a sequential work that took about T time units. This proof can be used to prove that a specific event occurred some duration of time ago. Let’s break down this…