Iota's anti-spam research for DAGs (e.g. Wesolowski VDF)

Iota's new Coordicide whitepaper has a section about rate limiting that mirrors a lot of the research that has been done in the Nano community (e.g. adaptive PoW vs dynamic PoW). One thing that caught my though was their research into Wesolowski VDF - mentioned as a potential complete replacement for adaptive PoW at some point:

In this section, we present a novel anti-spam mechanism for IOTA based on Wesolowski VDF [78] which aims to overcome the limitations of PoW (we choose the Wesolowski construction because it guarantees fast verification time and low overhead). The research on VDF is actively ongoing and this algorithm can be considered as a future replacement for adaptive PoW.

In order to bypass the VDF verification issue, they propose:

Unlike PoW, in VDF there is no trivial way to verify whether a node has indeed performed the work to obtain the output y. For this reason, we propose to attach an additional number, the proof, to help other nodes during the verification. In order to generate the proof, the node computes l = Hprime(x + y) and π = x b2 τ /lc. The summation between x and y ensures that the challenge has been successfully solved. In order to keep the transaction size small, the evaluator will only attach the resulting proof, i.e., the pair {l, π}, since the solution y can be inferred from it. The Algorithm 3 describes the evaluation and proof processed by a node.

Is this something that might be usable in Nano? Supposedly this VDF's output is very short and the verification process is efficient, but I don't know enough to verify that for myself.

5 Likes