Further reading
Every link below was checked to make sure it resolves and actually matches its description before going on this page.
The original paper
Dan Boneh, Joseph Bonneau, Benedikt Bünz, and Ben Fisch, “Verifiable Delay Functions” (CRYPTO 2018, pp. 757–788). The paper this whole site is built around: the formal Verifiable/Delay/ Function definition, the repeated-squaring construction, and the original application ideas.
The two independent proof systems
- Benjamin Wesolowski, “Efficient Verifiable Delay Functions” (EUROCRYPT 2019, pp. 379–407). The proof scheme this site’s own demo implements.
- Krzysztof Pietrzak, “Simple Verifiable Delay Functions” (ITCS 2019, LIPIcs vol. 124, pp. 60:1–60:15). The faster-to-generate, larger-proof alternative — see how it works for how the two tradeoffs compare.
Comparing the two
Dan Boneh, Benedikt Bünz, and Ben Fisch, “A Survey of Two Verifiable Delay Functions” (IACR ePrint 2018/712). Puts Wesolowski’s and Pietrzak’s schemes side by side with a unified security analysis — the clearest single source for why someone would pick one over the other.
A production deployment
Chia Network — Proof of Time (VDFs). Chia’s own documentation for the class-group-based VDF at the center of its consensus protocol — see Applications for how this site summarizes it.
Also see History for the earlier time-lock-puzzle work this research builds on, and Glossary for short definitions of the recurring terms.