Day 54: VDFs: Verifiable Delay Functions in Blockchain

Guilherme Soares
3 min readNov 25, 2023


Photo by Brett Jordan on Unsplash

“In the relentless march of blockchain, Verifiable Delay Functions are the rhythmic pause, ensuring fairness and unpredictability in the chain of blocks.” — Blockchain Theorist

As blockchain technology evolves, so do the mechanisms that underpin its security and efficiency. One such emerging concept is the Verifiable Delay Function (VDF), a cryptographic primitive gaining traction for its unique properties and applications in blockchain. Today, we delve into the world of VDFs, exploring their significance and how they contribute to the evolving landscape of blockchain technology.

Unpacking Verifiable Delay Functions

Verifiable Delay Functions (VDFs) are a cryptographic innovation that provides a way to enforce a time delay in computation. The key feature of a VDF is that it requires a specific amount of time to compute, even on parallel computing systems, but its output can be quickly and easily verified.

Core Characteristics:

  • Asymmetry in Time: A VDF takes a relatively long time to compute (delay phase) but produces a result that can be quickly verified.
  • Unparallelizable: The computation requires sequential steps, making it resistant to speed-up via parallel processing.
  • Deterministic: Given an input and a specified time delay, a VDF will always produce the same output.

VDFs in Blockchain: Enhancing Security and Fairness

In the context of blockchain, VDFs have multiple compelling use cases:

Preventing Front-Running in Decentralized Finance (DeFi):

  • VDFs can be used to prevent front-running attacks in DeFi platforms by ensuring that transactions are processed in a genuinely random order.

Improving Randomness in Consensus Mechanisms:

  • They can generate unpredictable, tamper-proof random numbers, enhancing the security and fairness of blockchain consensus protocols.

Time-lock Cryptography in Smart Contracts:

  • VDFs provide a way to create…



Guilherme Soares

I'm a senior software developer passionate about technology and to share knowledge.