Fhenix brings encrypted computation to blockchain applications, enabling privacy without compromising decentralization or composability.

Transactions on decentralized blockchains today are public, meaning that anyone can search a user's transaction history and find out exactly how many tokens they hold and what those tokens are. While this radical transparency to date ensures trustlessness, it also limits privacy-critical applications like DeFi, compliance, and sensitive data management. 

Without privacy, users and developers face serious limitations when building DeFi applications: private positions can't exist, sensitive data risks exposure, and regulated use cases remain out of reach.

This is where Fhenix steps in. 

Encrypted Computation with Fully Homomorphic Encryption (FHE)

At the core of Fhenix’s work is Fully Homomorphic Encryption (FHE). Today, most systems require encrypted data to be decrypted before it can be processed. This means that if you want to check if that data is accurate, you must briefly expose the information inside, posing a privacy risk. FHE enables encrypted data to be computed without the need for decryption. With FHE, data remains encrypted throughout the entire process. 

The introduction of FHE unearths a large number of new user cases for the blockchain, including but not limited to: encrypted identity frameworks, private trading and lending in DeFi, privacy-first DAOs and onchain applications that are capable of handling personal or business-sensitive data. It also brings new users, such as institutions, onchain. 

Fhenix began its journey with the Fhenix L2, an Arbitrum Nitro-powered rollup designed to secure data availability for encrypted computation. While effective, this rollup was a standalone solution.

Fhenix has since introduced coFHE: an FHE-powered coprocessor that lets developers write privacy-preserving smart contracts using familiar EVM workflows. With just one line of code, inputs, outputs, and logic stay encrypted, and only the data owner can decrypt the results. Built on Arbitrum, coFHE enablescomputations to be fast, secure, and offchain, making privacy accessible todevelopers.

“If you're building on Arbitrum, you can now enable encrypted computation using coFHE  in your app with just a single line of code, something that simply wasn't available until now,” Guy Itzhaki, Fhenix CEO, said.

Why Arbitrum?

When Fhenix first started building, its team actively sought infrastructure to support its long-term goals of bringing FHE technology to life. It needed technology that was fast and reliable, and built for developers. 

After evaluating the market, the team decided to work with Arbitrum’s Nitro Stack. Itzhaki explained that the Nitro stack was battle-tested, easy to use, and well documented. Most importantly, though, it was because Arbitrum had a fully functional fraud-proof system that could support encrypted data.

Arbitrum’s fraud-proof system enabled Fhenix to compile FHE logic into WebAssembly (WASM), which facilitated secure and efficient executions of encrypted computations. Without this, implementing FHE would have been challenging, as Ethereum does not natively support these operations. 

The Road Ahead

The latest implementation of coFHE on Arbitrum is just the beginning. Over the coming weeks, additional integration resources, documents, and announcements will be shared.

Looking forward, the Fhenix team will continue to expand coFHE to more EVM chains and develop ways to integrate real-world use cases into the blockchain space.  

Fhenix is also working closely with Tandem Studios, a venture company by Offchain Labs, to find ways to make FHE more accessible and practical for blockchain applications. This will pave the way for secure, decentralized, and private technology.

Developers who are interested in exploring Fhenix CoFHE further can start by getting access to their documentation. 

Get Started with Fhenix

If you want to build privacy-first applications, you can explore coFHE’s documentation, join the Fhenix developer community, or test it on Arbitrum today. Stay tuned for new integrations and real-world examples showcasing encrypted computation's power.

Disclaimer: Offchain Labs has a financial interest in Fhenix through investment and/or other commercial arrangements.