Solidity ecosystem day for people involved and interested in the Solidity language and the ecosystem around it. It features talks & discussions on Solidity, Yul, language design and tooling.

Solidity Summit

Main

We welcome you to the Solidity Summit, give and overview of the content of day, the venue, and everything else you need to know.

Opening & Welcome

Franziska Heintel

In the recent months, Solidity has introduced several exciting features that make it more flexible and safer at the same time, without compromising on performance. I would like to show you some examples of what is possible with the latest version of Solidity and explain some reasoning behind the features. The improvements do not stop there, though: We want to allow you to write generic code, improve the memory management and extract as much "magical code" from the compiler into a generic library as possible.

Solidity in 2022: Recent and Planned Features

Christian Reitwiessner

In the past year, we (Dedaub) have disclosed numerous vulnerabilities in deployed smart contracts and received 8 significant bug bounties totaling over $2.5M. The talk derives from this experience: I'll talk about the Dedaub tooling (including the contract-library.com code explorer) and a couple of Solidity patterns that have been behind high-value vulnerabilities we've identified. The main body of the talk, however, will focus on a simple question: "what can I do as a developer to make my smart contract auditor more efficient and effective?" This is not much different from asking "how can I write better code?" but I intend to give actionable advice, based on numerous audits (and instances of hair pulling).

Thanks for all the bugs!

Yannis Smaragdakis

Make an approach to good practices on events emission, to introduce to Sol developers an idea on how to model the event database so that the information is available for posterior data analysts. I see a lot of gas saving discussions, and none on good data practices, as well as very few clean data dashboards, because of hacky implementations.

Good practices from a Data Analyst perspective

wei3erhase

The smart contracts for float.capital make use of lots of small, inter-dependent, internal functions.

The best solution we could find to solve these issues at the time was smock (which is probably still the best option), however this only allows mocking of external functions.

As a solution to this, we built a code-generation tool that built out modified smart contracts that externalised all internal functions to call out to an external contract so that we can selectively turn on mocking for any internal function and use smock on any internal function. All this code was generated by looking at the AST, abi and contract code in the code-gen process. We are currently in the process of experimenting with how we can use similar techniques in forge/foundry contract testing.

Mocking of internal functions in Solidity Unit Tests

Jason Smythe

I would enjoy talking about various interesting things you can do using `create2`. That goes all the way from proxies that don't need to explicitly store owners, to crosschain address oracles and fancy bridge escrowing systems.
I want to highlight a couple of these different approaches and how they are used in deployed applications.

Create 2 patterns

Fred

We will go through examples of using Foundry in the real-world™️ and also see how we can easily migrate existing testing suites to Foundry.

Foundry 101, a hands-on introduction

odysseas

At DethCrypto we are working on dev tooling for crypto. You might have used typechain, eth-sdk, earl or deth code. I would briefly go through those tools and then talk about the Solidity profiling service we are building and unique features it will provide.

dΞth Crypto

Leo Logvinov

Remix Hybrid tools to help drafting and developing dapps.

Remix Hybrid Tools

Aniket

Truffle's ultra-powerful @truffle/decoder package, a high-level interface for decoding transactions, events, and state variables for Ethereum smart contracts.

Presenting @truffle/decoder

G. Nicholas D'Andrea

Goodbye YOLO-Signing! Sourcify's source code verification via contract metadata enables human-friendly contract interactions and provides byte-by-byte (perfect) matches of the deployed contract. The talk encompasses how perfect matches work, how can you use Sourcify, and what Sourcify's vision for better contract interactions is.

Human-Friendly Contract Interactions with Sourcify Verification

Kaan Uzdogan

We present two open-source analysis tools developed by Veridise, a new software auditing company for smart contracts. First, Vanguard is the first cross-chain tool that finds vulnerabilities in smart contracts by looking for common patterns. Second,  Eurus, uses symbolic execution to discover vulnerabilities in smart contracts. Unlike other analysis tools both Vanguard and Eurus provide users with concrete evidence of exploitability. In this talk, we showcase the functionality of these tools and examine how they can automatically generate complex attacks on smart contracts such as flashloan attacks.

Hybrid Attack Synthesis for DeFi

Jon Stephens

What PRBMath is needed for and the most popular use cases

PRBMath: A Smart Contract Library for Fixed-Point Math

Paul Razvan Berg

We've been working on a Solidity debugger for IntelliJ this past few months and we'd like to demo it.

IntelliJ Solidity Debugger

Conor Svensson

Exploring how Solidity would look like if it were designed today, with everything we know about both language development and smart contract development. Including, but not limited to: tooling, zero-cost abstractions, type system, etc. These features can even be added to Solidity in the future if there is demand!

What would Solidity look like if it was built today?

John Adler

An overview of how Yul has been used in Fe's development. We will discuss how we use Yul to generate bytecode for a high-level language and go over the Rust tooling that assists us.

Bootstrapping a Compiler with Yul

Grant Wuerker

There is a lot of mystery behind the Solidity optimizer. Understanding the optimizer would allow one to write contracts that are readable while also being gas efficient. This is especially important for the ``viaIR`` pipeline as it enables the compiler to perform complex optimizations. The talk will give an overview of some optimization steps, with a focus on how it affects real world code!

The Solidity Optimizooooor

Hari Mulackal

While Yul is a low-level language that provides only a thin abstraction over the bare opcodes of the EVM, the transition from Yul to EVM bytecode still leaves room for certain choices: most obviously the control-flow structures of Yul have to be translated to plain jumps in the EVM. But furthermore, Yul does not presuppose the layout of its variables on the EVM's stack - and due to the fact that the EVM merely allows access to the 16 top-most values on its stack, the precise construction of suitable stack layouts and transitions between them is particularly important.
In this talk, I will sketch the inner workings of the Yul-to-EVM code transform used in the new via-IR compilation pipeline with enabled optimizer. I will discuss its advantages over the more naive approach used for Yul components in the legacy compiler pipeline, how it interacts with the Yul optimizer to move variables from stack to memory to avoid stack-too-deep errors and what further improvements can be expected in the near future. Lastly, I will hint at the challenges this new mechanism presents for tooling and debuggers.

Generating EVM bytecode from Yul in the new via-IR pipeline

Daniel Kirchner

The winners of this year's Underhanded Solidity Contest will present their submissions.

Underhanded Solidity Contest Winner Presentations

Tynan Richards

Santiago Palladino

Michael Zhu

Facilitate knowledge transfer between applied ZK developers at different levels of the stack, demonstrate the importance of application-specific ZK technology, and increase the legibility of ZK crypto to the crypto space broadly.

Applied ZK Workshop

Day #1

Day #2

Opening remarks

Brian Gu

This talk presents zkAttestor, a project to produce trustless zkSNARK-based on-chain attestations to data from any Ethereum state or block. These attestations are trustlessly verified on-chain in a smart contract which caches historical block hashes.  We envision use cases including identity, dapp primitives involving history, and on-chain reputation.

zkAttestor: Block and State Attestations on Ethereum

Yi Sun

Interep is an anti-sybil mechanism providing a bridge from an established identity source to the Ethereum ecosystem. It does so while preserving privacy. We'll discuss the potential use cases.

Interep - Identity in the web3 world

Geoff Lamperd/ Cedoor

Exploration of the cryptography primitives and data structures used in UniRep, a protocol enabling users to give, receive and prove reputation anonymously. We’ll also demo UniRep Social, a Reddit-like social app using the UniRep protocol.

Unirep and Unirep Social

Vivian Jeng and Barry Whitehat

We'll look at Waku, the communication layer for Web3, and how it uses ZK for its service network. Specifically, we'll look at RLN-RELAY, a privacy-preserving p2p economic spam protection mechanism. We'll also look briefly at the history of different implementations, and how we plan to get the best of both worlds with Rust and Circom using ark-circom and Zerokit.

Private, economic spam protection in Waku with RLN

Oskar Thoren

We're presenting cabal.xyz, a way to gate discord servers with ETH information while hiding your identity.

cabal: anonymous internet clubs

Lakshman Sankar (+ Uma Roy)

Minion fight is a zero-knowledge incomplete-information card game where private information such as hands and decks are simulated on chain. Each player gets a set of cute minion cards with different abilities and battles against a friend!

zk card game

Abby Lu

Diving into the design of a generalized marketplace that can exchange any asset type. Introduce a new token interface for private data and a demo of its use.

ZK Data Marketplace

Nick Ulven

We present a demo, explanation, hack, and fix of stealthdrop, the first OSS zero knowledge airdrop protocol.

Stealthdrop

Aayush Gupta

Nalin Bhardwaj

Adhyyan Sekhsaria

We introduce and demonstrate a dApp with a zkSNARK prover/verifier for a simple computer vision deep learning convolutional neural network for handwritten digit recognition (MNIST). This enables on-chain verification of off-chain, private data. Potential applications of this type of zk technology may include the protection of sensitive and private information such as personal financial info, personal biometric info, or private video/audio/image data.

A zkMNIST dApp

Francis Ho and Horace Pan

We'll describe what RLN is, why it is important, as well as recent developments and real world applications.

RLN and RLNapplications in the real world

Blagoj Dimovski

UltraPLONK is an extension of PLONK that supports custom gates and lookup arguments. In this talk, we introduce abstractions such as the "matrix" picture of the circuit, regions, and gates; then, we break these down to understand how they translate into polynomials that constrain a witness. We also explain optimisations, like floor-planning and selector combination, that improve the circuit layout.

UltraPLONK Arithmetisation

Ying Tong Lai

We present implementations of ECDSA, elliptic curve pairings, and RSA in circom, as well as some of their applications.

Elliptic Curves, Pairings, and RSA in Circom

Brian Gu / Yi Sun

Ecne

Franklyn Wang

Presenting ongoing work on formal verification for ZK circuits using symbolic compilation, showing preliminary results and potential directions for future work.

Formal Verification for ZK Circuits Using Symbolic Compilation

Yu Feng

zkREPL is a fully in-browser development environment for zk-SNARKs written in Circom

zkREPL

Kevin kwok

Building, playing, and hacking on crypto-native games. Participants: Dark Forest, Lattice, Conquest.eth, Topology, DFDAO, 0xCurio, and Moving Castles.

D.E.F.CON

DeFi Day is dedicated to everything DeFi, hosted in Amsterdam, on the 25th of April. We are excited to further the Defi ecosystem by bringing DeFi developers, working on applications and infrastructure layer together.  

DEFI DAY

DeFi Day

Amsterdam will be hosting Devconnect for a week, gathering the brightest developers and Ethereum builders. This event is for all the curious minds, technically inclined and generally interested people wanting to learn from the best contributors of the Ethereum ecosystem.

ETH DAY

Morning

Afternoon

Launch of ETH day

The cryptocurrency industry is made of visionaries and ruthless money makers, the perfect mix for a monetary revolution, and Eléonore is all in. Thrilled to be part of an ongoing social and financial experiment, she's passionate about p2p cash, voluntarism and economic freedom.
She founded CryptoCanal in 2019, offering education, events and consultancy services (marketing and business development). She's worked with industry leaders such as BTC.com, Luno, OKEx, Bitcoin.com, Cyber Capital and Bitvavo. She  hosts the bi-monthly CryptoCanal meetup in Amsterdam and teaches an online Crypto 101 for all and an in-depth class for more advanced cryptocurrency investors. She’s the host of the Humans of Crypto Podcast.

Eléonore Blanc

Welcome to Devconnect!

Aya originally became fascinated in the blockchain space for its potential to impact financial inclusion in emerging economies. In early 2013, she joined Kraken and educated the public, regulators, VCs and media on cryptocurrencies and blockchain innovation globally as Managing Director of Japan. Her passion for creating lasting sustainable impact led her to join the Ethereum Foundation as Executive Director. There, she leads the Foundation’s work to support the Ethereum ecosystem through core research and development activities, financial support and guidance, and cross-sector educational efforts. Aya’s goal is to help Ethereum maintain its soul as an Infinite Garden, or a decentralized creative space that is open-source, inclusive and permissionless.

Aya Miyaguchi

Time for an Update on the Ethereum Roadmap

Tim Beiko is the coordinator for Ethereum's AllCoreDevs calls. Prior to this, we worked on ConsenSys's Ethereum client, Hyperledger Besu.

Tim Beiko

Why community funded core developent is a Public Good

Ethereum community member that has been involved with a number of public goods projects through Stateful Works. Currently working at the EF on the Protocol Support team, connecting client teams and researchers with the broader ecosystem.

Trent van Epps

First principles for DAO design

Andrej Berlin

Learn from the serial DAOists

Rolf is a serial DAOist, Member of the @Meta_Cartel Mages, Owner at @cultur3capital & Builder at @numomoart

Rolf Hoefer

Ryan is a DAO coordinator working to build a better world full of vibrant Public Goods.

Ryan Coordinator

Project Lead (SES), Co-Founder (CW), Co-host (meetup)

Lenka Hudáková

Digging Into DeFi

Jeremy Musighi is Head of Growth at Balancer Labs, supporting the community-driven growth and sustainability of the Balancer Protocol. He has also been a crypto investor and researcher since 2013 and is the founder and CIO of Immutable Capital. Jeremy previously co-founded, grew, and sold two consumer Internet technology companies.

Jeremy Musighi

DeFi surfing the highs and lows

Blockchain OG. DeFi Builder. HW Eng. First Flash Loan of the history. Massive tech investor "The more your share, the more you get”

Julien Bouteloup

Alex Vinas is the marketing manager at CowProtocol, a spinoff of GnosisDAO that offers a batch settlement layer for decentralized trading. Prior to joining CoW, Alex worked as a financial and innovation consultant specializing in enterprise blockchain for leading institutions in Spain.

Alex Vinyas

Pushing forward blockchain adoption #BUIDL

Jonathan Knegtel

Tools & Infrastructure

Simon is enthusiastic about simplifying the complexities of our interconnected world. He applies this passion as a Solutions Engineer at Edge & Node to enable the amazing projects in web3 building exceptional decentralised experiences leveraging The Graph. He joined the blockchain space professionally in 2017 as Head of Front-end/UX at Melonport which is now know as Enzyme Finance, one of the pioneering projects using The Graph.

Simon Emanuel Schmid

DevRel and Community lead @Consensys & Early Stage Investor at @ouicapital , Former Developer Community at @digitalassetcom and NFT lover

Francesco Andreoli

Austin Griffith

Debate: NFTs

After studying philosophy at the University of Auckland in New Zealand, Justin discovered crypto assets in 2013 and immersed himself in this new technology. This led him to actively invest and research cryptocurrencies full-time in 2014 as a generalist with a specialization in the politics and decentralized governance of cryptocurrencies. In BTC’s development, Justin was involved in block-size debates in favor of larger blocks and supported the software implementations of BTC XT, BTC Classic and became a member of BTC Unlimited. Over time, with a critical mindset towards evaluating cryptocurrencies including, Justin has developed his own theories on blockchain governance as a major factor to the competitive evolution of cryptocurrencies. Through writing articles, giving lectures and regularly participating in public debates surrounding cryptocurrencies, he gains insights to further hone the fundamental analysis-based investment strategy that remains his primary focus.

Justin Bons

Adrian is the founder of @EthBlockArt, the NFT protocol and creative engine for blockchain based data art.

Adrian le Bas

Working in Web3

Maria Magenes entered the world of Blockchain and in particular of Decentralized Finance (DeFi) in 2018. Today she is Marketing Lead of Oasis App, the DApp that allows access to the Maker protocol and the creation of Dai. In addition, she collaborates with Balancer Labs, another important DeFi project and with other projects related to the blockchain. Previously Maria held the role of Community & Marketing Lead Europe & Africa for the Maker Foundation and Head of Marketing for Aave for 2 years. Before entering the world of blockchain, she was part of the Marketing Strategy team at Sky Italia for several years. Maria studied International Business at Bocconi University and is passionate about technology and innovation.

Maria Magenes

ETH as an economic asset is critical to the security of Ethereum. RIG, economists, and others spend a day teasing apart the economics of ETH

ETHconomics

Ask Remix Anything and play the Remix virtual obstacle course through contract development.

Game Day Remix

A two-day technical conference dedicated to Ethereum L2 Scaling. Meet industry leaders: builders and developers, learn during talks and panels and dig deeper by attending workshops.

Layer Two Amsterdam

ZK Track

Beyond Rollups

How we are building the zkEVM

Jordi leads the technical development of the Polygon Hermez zkRollup and is currently working on the implementation of the zkEVM. He is the co-founder of the White Hat Group, the author of the MiniMe token contract, the elliptic curves Solidity library, as well as numerous other established contracts in the Ethereum space. Jordi is also a well-respected auditor as well as the co-founder of the donation platform Giveth, DAppNode, Iden3 and most recently, Polygon Hermez.

Jordi Baylina

Polygon Nightfall and testnet launch update

Chaitanya is a Cryptography and Blockchain Researcher working in EY's Blockchain R&D team. She works on scalable privacy solutions for public blockchains. She led the development of Nightfall 1 project and currently is leading the deployment of Polygon Nightfall to mainnet in partnership with Polygon.

Chaitanya Konda

Building Scalable L2s with ZK

Brendan studied math and philosophy before starting Mir, a ZK L1 designed to provide privacy and scalability. The Mir team joined Polygon, becoming Polygon Zero, and released Plonky2, which set a new benchmark for ZKP performance. Polygon Zero is focused on building a scalable ZK L2 to onboard the next billion users to Ethereum.

Brendan Farmer

Miden VM: the heart of Polygon Miden

Bobbin Threadbare is a project lead for Polygon Miden. Prior to joining Polygon, Bobbin was a core ZK researcher at Facebook's Novi where he led the development of Winterfell, a highly-performant STARK prover and verifier. Bobbin has made numerous contributions to the STARK-based systems including genSTARK library, Distaff VM, as well as AirScript and AirAssembly languages.

Bobbin Threadbare

Anonymity for a billion people

Desire: To see humanity explore and enjoy the full extend of what is possible within the limits of the laws of physics, and to find ways to hack around those limitations where I can!

Remco Bloemen

A look into the zk-evm

Olivier Bégassat is part of the ConsenSys Applied Research RnD team. His current interest is around developping a zk-evm.

Olivier Begassat

Theodore Chapuis-Chkaiban is an applied researcher in Cryptography at ConsenSys Protocols R&D team. His research interests lie at the intersection of cryptography and computer architecture design. He is the co-author of a paper recently published on EthResearch specifying a model for a zk-EVM which is currently being implemented.

Théodore Chapuis-Chkaiban

zkEVM challenges and solutions

Ye Zhang is the co-founder and zk-researcher at Scroll Tech. He used to work on hardware acceleration for ZKP algorithms and theoretical constructions behind ZKP protocols. Now his focus is on optimizing the zkEVM.

Ye Zhang

Do we need zkEVM equivalence or is EVM compatibility sufficient?

Justin is a researcher at the Ethereum Foundation.