EthereumZuri.ch 2025

How to Do Confidential Transactions Directly on Ethereum
01-30, 13:15–14:15 (Europe/Zurich), Sepolia Stage

Have you ever wanted to implement real-world applications such as private transfers, confidential voting systems, decentralized identity management, and private NFTs on Ethereum?

If yes, then this workshop is for you! In "How to Do Private/Confidential Transactions Directly on Ethereum," learn how to leverage Zama's Fully Homomorphic Ethereum Virtual Machine (fhEVM) to build confidential smart contracts. With the fhEVM, you can create privacy-preserving applications by performing computations on encrypted data, ensuring confidentiality without sacrificing the composability of smart contracts. By the end of this presentation, you'll have hands-on experience deploying private smart contracts using encrypted types and operations.


This workshop is designed for developers who want to leverage Zama's fhEVM to enable confidential transactions on Ethereum, including use cases such as private transfers, confidential voting systems, decentralized identity, private NFTs, and even secure state registries. Participants will learn how Zama's integration of Fully Homomorphic Encryption (FHE) into Solidity smart contracts allows for the execution of transactions and operations on encrypted data, ensuring privacy without compromising the composability of onchain applications.

Key workshop components include:

  • Setting up the fhEVM development environment
  • Getting an overview of how the fhEVM works behind the scenes
  • How to write basic confidential smart contracts
  • When to encrypt, decrypt and re-encrypt
  • Security considerations when creating real-world applications: private transfers, confidential NFTs, secure decentralized voting etc
  • Deploying and interacting with confidential contracts on Sepolia

By the end of the session, participants will have a deep understanding of how to build and deploy privacy-preserving smart contracts on Ethereum using Zama's fhEVM, enabling them to integrate secure, private features into their dApps.

Key workshop components include:

  • Setting up the fhEVM development environment
  • Getting an overview of how fhEVM works behind the scenes
  • How to write basic confidential smart contracts
  • When to encrypt, decrypt and re-encrypt
  • Security considerations when creating real-world applications: private transfers, confidential NFTs, secure decentralized voting etc.
  • Deploying and interacting with confidential contracts on Sepolia

By the end of the session, participants will have a deep understanding of how to build and deploy privacy-preserving smart contracts on Ethereum using fhEVM, enabling them to integrate secure, private features into their dApps.

Aurora Poppyseed is a developer relations engineer at Zama, where she focuses on promoting fully homomorphic encryption solutions for blockchain and machine learning. With past experience as the co-founder and CTO of Lastic, she is now dedicated to making complex development topics understandable for everyone. Aurora is passionate about bridging the gap between advanced technologies and developers by creating accessible educational content and tools, aiming to simplify cryptography and blockchain for a broader audience.