VDF Research Effort

This is a collaborative effort to design and implement efficient VDF in software and in hardware, to make VDFs secure and usable in real systems.

What are VDFs?
Verifiable Delay Functions take a prescribed time to compute, even on a parallel computer, yet produce a unique output that can be efficiently and publicly verified.

Why do we need them?
VDFs have a wide variety of decentralized systems: public randomness beacons, leader election in consensus protocols, and proofs of replication.

Can we use them today?
Efficient VDF constructions exist today and can be implemented. However, if malicious actors have access to specialized hardware they can speed up their evaluation, breaking the security of the protocols that rely on VDFs :(

So, what's next?
Ethereum Foundation, Protocol Labs, academic institutions and other collaborators are working towards designing and open-sourcing the fastest VDF hardware :)

  • Collaboration: We are open to collaborate with academic institutions, manufacturers that can help improving our constructions and projects that want to participate in this effort.
  • VDF Competition: We are organizing a competition to research the fastest VDF construction, get your maths and circuit optimization ready! TBA

Stay tuned or reach out vdf (at) ethereum.org


2018 (30 July)—Boneh, Bünz, Fisch A Survey of Two Verifiable Delay Functions

2018 (22 June)—Pietrzak Simple Verifiable Delay Functions

2018 (20 June)—Wesolowski Efficient Verifiable Delay Functions

2018 (12 June)—Boneh, Bonneau, Bünz, Fisch Verifiable Delay Functions

2015—Lenstra, Wesolowski A Random Zoo: Sloth, Unicorn, and Trx

Randomness beacons

2018 (26 September)—Drake Minimal VDF Randomness Beacon

2018 (16 July)—Drake VDF-based RNG with Linear Lookahead

2018 (8 June)—Jensen, Kristensen, Michno Developing a Trustworthy Randomness Beacon for the Public

2017—Bünz, Goldfeder, Bonneau Proofs-of-delay and Randomness Beacons in Ethereum

2016—Darknet RANDAO: A DAO Working as RNG of Ethereum

1998—Goldschlag, Stubblebine Publicly Veriable Lotteries: Applications of Delaying Functions

Other relevant reading

2018 (21 July)—Buterin STARKs, Part 3: Into the Weeds

2018 (9 Feb)—Cohen, Pietrzak Simple Proofs of Sequential Work

2014—Gnos1s RSA UFO

2013—Mahmoody, Moran, Vadhan Publicly Verifiable Proofs of Sequential Work

2001—Buchmann, Hamdy A Survey on IQ Cryptography

2000—Boneh, Naor Timed Commitments

1999—Sander Efficient Accumulators without Trapdoor Extended Abstract

1996—Rivest, Shamir, Wagner Time-lock Puzzles and Timed-release Crypto


Oct 2018—Arthur Breitman Better randomness

Oct 2018—Trail of Bits Introduction to Verifiable Delay Functions (VDFs)

Sep 2018—Justin Drake Minimal VDF randomness beacon

Aug 2018—Jeromy Johnson A VDF Explainer

Jul 2018—Danny Ryan VDFs are not Proof of Work

Apr 2018—Anatoly Yakovenko Proof of History: A clock for blockchain


2018—Ben Fisch Verifiable Delay Functions: Applications and Candidate Constructions

2017—Benedikt Bünz Proofs-of-Delay and Randomness Beacons in Ethereum

2017—Joseph Bonneau Verifiable Lotteries