Devcon Archive logo
Devcon Forum Blog
  • Watch
  • Event
    Event: background logo
    • Devcon 7
    • Devcon 6
    • Devcon 5
    • Devcon 4
    • Devcon 3
    • Devcon 2
    • Devcon 1
    • Devcon 0
  • Categories
    Categories: background logo
    • Cryptoeconomics
    • Devcon
    • Developer Experience
    • Coordination
    • Core Protocol
    • Layer 2s
    • Real World Ethereum
    • Cypherpunk & Privacy
    • Security
    • Applied Cryptography
    • Usability
  • Playlists

Suggested

Loading results..

View all

About Devcon —

Devcon is the Ethereum conference for developers, researchers, thinkers, and makers.

An intensive introduction for new Ethereum explorers, a global family reunion for those already a part of our ecosystem, and a source of energy and creativity for all.

  • Watch
  • Devcon
  • Forum
  • Blog

Get in touch

devcon@ethereum.org

Subscribe to our newsletter

Crafted with passion ❤️ at the Ethereum Foundation

© 2025 — Ethereum Foundation. All Rights Reserved.

devcon 5 / hands on applications of zero knowledge signalling

  • YouTube
  • IPFS
  • Details

Hands-on applications of zero-knowledge signalling

Duration: 00:54:50

Speaker: Wei Jie Koh

Type: Breakout

Expertise: beginner

Event: Devcon

Date: Invalid Date

Semaphore is a generalised zero-knowledge signalling system which can be deployed to fulfil various privacy use cases, such as a mixer and anonymous whistleblowing. This hands-on workshop will guide participants through a high-level explanation of how Semaphore and zero-knowledge proofs work, and guide them through an anonymous chat app integrated with POAP tokens which can generate and verify said proofs. No programming or zk-SNARK knowledge is needed.

Categories

Privacytechnical
  • Related
A trustless Ethereum mixer using zero-knowledge signalling preview
Devcon
Breakout
19:08

A trustless Ethereum mixer using zero-knowledge signalling

Since Ethereum transactions are fully visible on-chain, it is possible to trace value transfers and surveil users' financial activity. This state of affairs deprives users of privacy beyond mere pseudonymity. Some workarounds, like using a centralised exchange wallet or a custodial mixing service, however, introduce a high degree of counterparty risk. The Ethereum ecosystem needs a noncustodial mixer which works through strong cryptography, rather than blind trust. To solve this, we present a trustless mixer for Ether and ERC20 tokens. It builds upon Semaphore, a zero-knowledge signalling system by Barry WhiteHat and Kobi Gurkan. Additionally, it employs a burn relay registry which incentivises third parties to pay gas fees on behalf of mixer users. In this presentation, I will show a high-level architectural overview of the mixer, dive into its underlying zero-knowledge circuits, and discuss other applications of zero-knowledge signalling.

Zero Knowledge: Privacy and Transparency's beautiful co-existence preview
Devcon
Breakout
17:49

Zero Knowledge: Privacy and Transparency's beautiful co-existence

Zero Knowledge Systems are often imagined as the enabler technologies for a privacy-centric world in which an individual can operate freely, away from public scrutiny. In these proposals, we focus primarily on an individual's right to own and protect their private data. While this is an important topic to us all and a model that is already being explored by projects like Zcash, I believe that the Zero Knowledge paradigm actually offers an opportunity for something even more powerful: that is secure systems providing both privacy and at the same time transparency for individuals and organisations. In this talk, I aim to explore what this balance can look like using zero knowledge systems, how valuable this could be in our personal and business lives, and showcase projects aiming to develop tools in this spirit.

Keynote: Lessons learned from Tor preview
Devcon
Talk
31:51

Keynote: Lessons learned from Tor

I will share lessons learned during Tor's twenty years as free software fighting for privacy and human rights. We'll talk about distributed trust and privacy by design, how to help people understand the good uses of your tech, getting allies in both cypherpunks and government, why transparency and community-building are so essential to trust, and successes from other spaces. It may seem like the crypto wars never really end, but we all have a part to play in saving the world.

Keynote: Make Ethereum Cypherpunk Again: Why we need privacy preview
Devcon
Talk
26:12

Keynote: Make Ethereum Cypherpunk Again: Why we need privacy

The Web3 revolution seeks to address the sins of Web2. However, in doing so, it’s created an even worse outcome for users - users’ data is publicly available and makes them vulnerable to state-level censorship and adverse actions. This talk will address the philosophical as well as practical considerations of privacy in Web3. Privacy is an industry-wide issue and sits at the heart of all that is Web3. Understanding why privacy matters involves recognizing that it is not an isolated concept bu

Keynote: Glass Houses and Tornados preview
Devcon
Talk
15:04

Keynote: Glass Houses and Tornados

The Tornado Cash sanctions and criminal prosecutions have challenged longstanding assumptions within crypto about the limits of money transmission licensing, money laundering statutes, and sanctions laws. They've also revealed a longstanding assumption from some in policy and law enforcement circles: that blockchains have always been and must remain transparent. Neither assumption has served us well and the time has come for legal certainty. This talk is about how we get there.

Tending the Infinite Garden: Organizational Culture in the Ethereum Ecosystem preview
Devcon
Talk
23:47

Tending the Infinite Garden: Organizational Culture in the Ethereum Ecosystem

This presentation will discuss the findings of the academic paper "Tending the Infinite Garden: Organisational Culture in the Ethereum Ecosystem" by Dr. Paul-Dylan-Ennis and Ann Brody. Our study examines the decision-making processes fundamental to Ethereum's protocol governance, drawing on interviews with Ethereum's core developers. We identify a central worldview in Ethereum known as the "Infinite Garden" and discuss how Ethereum's social layer is crucial for upholding cypherpunk values.

Decentralizing Ethereum Data with VulcanizeDB preview
Devcon
Talk
31:52

Decentralizing Ethereum Data with VulcanizeDB

Ethereum is a robust platform for decentralized applications, but the same data structures and encodings that make it effective and trustless also complicate data accessibility and usability. How do you know token balances were updated correctly after you sent your transaction? Is an address authorized to seize your assets? How have system parameters changed over time? To answer these questions, we’ve traditionally depended on centralized APIs and block explorers to capture and serve historical data in a performant way. But what if those services shut down or returned modified results? VulcanizeDB has been working hard to address this problem - aiming to make it easier for anyone to set up, maintain, and query their own data directly. The good news: it is possible to keep track of the historical state of smart contracts without storing petabytes of data! The tricky part: you need to be intentional about how you track information, and you need to aggregate data from disparate sources to provide a holistic view. This workshop will provide a demo and hands-on experience walking through how VulcanizeDB simplifies the process of developing and interacting with smart contracts while keeping our applications and data independent of centralized third parties.

Decentralizing Transaction Abstraction for On Chain Privacy preview
Devcon
Breakout
26:48

Decentralizing Transaction Abstraction for On Chain Privacy

Transaction abstraction (or meta transactions, if you prefer) isn't a new idea in Ethereum. The idea, roughly, is that users sometimes want a 3rd party, called relayers, to pay gas for their transactions for them. To support on-chain privacy apps like the MicroMix mixer, we've designed a decentralized transaction abstraction system with 2 particularly novel ideas:a transaction simulation engine that allows anyone to run a relayer with minimal configurationa trustless reputation/spam-prevention system for relayers, that we call the 'burn registry' In this talk, I'll:present the design space of transaction abstraction and some of the crypto-economic challenges in building such a systempresent the solution we've built for MicroMix and finally, share software that you can run today to be a relayer on our network.

Ethereum 9¾: MimbleWimble for ERC20 with ZK Snark preview
Devcon
Breakout
18:50

Ethereum 9¾: MimbleWimble for ERC20 with ZK Snark

Ethereum 9¾ is an entrance to the magical world to send ERC20s privately. It hides the transaction histories using MimbleWimble and ZK Snark. A user enters into the magical world by depositing ERC20 tokens with a valid MimbleWimble output. As Ethereum 9¾ appends it as a coin-base to the Merkle Mountain Range tree, the user becomes able to use MimbleWimble spell to send ERC20 privately. The contract only accepts MW spells which include an unlinkable spent tag, result outputs, and a ZK proof. The proof should pass the ZK-circuit which ensures that the tag is derived from an output which definitely exists in the MMR tree while the sum of spent and resulting outputs satisfies the MimbleWimble equation. Then, the spent tag prevents double-spending and ZK Snark secures deposited ERC20s by proving that the sum of inflow and outflow is zero by MimbleWimble protocol without revealing details. Or the user can go back to the muggle world anonymously and withdraw ERC20s by providing an unlinkable spent tag and a ZK proof. Because MimbleWimble doesn't reveal the value during transactions and we also don't know which output has been spent, it becomes hard to link the deposit and withdrawal.

KeySpace: End-to-End Encryption using Ethereum and IPFS preview
Devcon
Breakout
33:36

KeySpace: End-to-End Encryption using Ethereum and IPFS

One of the interesting side effects of the number of developers coming into the blockchain space is that as more engineers come to understand & play with cryptographic tools, they are more likely to come up with solutions to new user experience issues by creatively applying these cryptographic primitives. At AirSwap we wanted to enable conversational, messaged-based trading for users, and support dependable message delivery, without compromising their privacy. Since we knew that all dApp users have access to a persisted public-private key-pair through their wallet, we built a system that allowed them to derive secondary PGP keys which were deterministically tied to their address, and allowed for encryption & decryption of messages, and also signatures and signature verifications. (more detail here: https://medium.com/fluidity/keyspace-end-to-end-encryption-using-ethereum-and-ipfs-87b04b18156b)In this workshop, I’ll help participants walk through the creation of their KeySpace key pairs using their Ethereum wallet of choice (Trust, Coinbase Wallet, Ledger, Trezor, etc) via the functionality provided in the AirSwap.js library (https://github.com/airswap/AirSwap.js). Afterwards they will be able to validate identities in decentralized messaging systems, encrypt & decrypt messages sent over IPFS (via OrbitDB), and build the foundation for permissioned, off-chain applications.Participants will need a laptop, understanding of git, and basic javascript development skills (installing from NPM, writing code in an IDE of choice).