Fhenix, the privacy-focused startup, has officially launched its CoFHE coprocessor on both the Ethereum and Arbitrum mainnets. This pivotal development, announced on Wednesday, October 21, 2026, ushers in a new era for confidential computing on public blockchains, allowing smart contracts to process sensitive data without revealing underlying values.
The CoFHE system, built on advanced fully homomorphic encryption (FHE) technology, enables on-chain operations with encrypted balances, positions, and trading strategies. This means that while transaction rules remain enforced by the smart contract, the specific financial details stay private, addressing a core transparency challenge inherent to traditional blockchain designs.
Fhenix encrypted balances on-chain
Public blockchains like Ethereum are, by design, transparent. Every transaction, every wallet holding, and every smart contract interaction is visible to anyone. While this fosters trust and auditability, it poses significant privacy concerns for individuals, financial institutions, and businesses seeking to leverage blockchain technology without exposing proprietary data.
Fhenix’s mainnet launch directly tackles this dilemma. By allowing contracts to compute on encrypted data, the platform offers a pathway for decentralized applications (dApps) to handle sensitive information—such as bidding strategies, private voting, or confidential financial transactions—while maintaining the integrity and decentralization of the underlying network.
How Fhenix’s CoFHE coprocessor works
At the heart of Fhenix’s offering is the CoFHE coprocessor. This off-chain component is designed to handle the computationally intensive operations required for fully homomorphic encryption. It performs calculations on encrypted data and then passes the encrypted results back to the smart contracts on the Ethereum and Arbitrum networks.
Developers can integrate this advanced functionality with relative ease, using a simple Solidity import and encrypted data types that behave much like standard variables. This abstraction simplifies the complex cryptographic processes, making FHE accessible to a broader range of blockchain developers. Fhenix provides FHE Solidity Libraries with encrypted integer types and homomorphic operations, alongside a Cofhe.js Client Side Library (TypeScript SDK) for frontend applications.
Dual-mode tokens unlock privacy
Alongside its coprocessor, Fhenix has introduced a dual-mode token design, now also in production. This innovative standard allows tokens to exist in both a public and a confidential mode, offering users flexibility and control over their financial privacy. A holder can seamlessly switch a balance into confidential mode with a single transaction.
Crucially, these dual-mode tokens never leave their native chain and are not wrapped or bridged, ensuring compatibility with existing blockchain infrastructure. They continue to function with established wallets, exchanges, and decentralized finance (DeFi) applications, removing significant hurdles to adoption. This approach maintains the integrity of token supply and minimizes smart contract risk.
The technical bedrock of Fully Homomorphic Encryption
Fully Homomorphic Encryption (FHE) stands as a foundational cryptographic method that enables computation on encrypted data without ever needing to decrypt it. The concept first emerged in 1978 with Rivest, Adleman, and Dertouzos, but it was Craig Gentry’s work in 2009 that provided the first feasible construction using lattice-based cryptography.
For blockchain ecosystems, FHE represents a significant leap. It addresses the inherent transparency that can expose sensitive information, offering a robust solution for private transactions, intellectual property protection in smart contracts, and data privacy across various sectors.
Though traditionally challenged by high computational costs, Fhenix claims its FHE blockchain offers significantly lower latency and higher throughput compared to previous threshold FHE benchmarks.
Fhenix’s founder, Guy Zyskind, along with Professor Chris Peikert, notably had their research on threshold FHE decryption accepted as a Distinguished Paper at ACM CCS 2025, underscoring the advancements in making FHE scalable for multi-party systems.
Fhenix’s CoFHE architecture distinguishes between on-chain and off-chain components. On-chain, Solidity libraries manage encrypted values and operation requests, while off-chain, a Client SDK and ZK Verifier process and verify encrypted inputs. This separation streamlines operations and enhances scalability, moving heavy computational tasks away from the mainnet.
Early applications and institutional confidence
Fhenix’s mainnet debut isn’t just a technical rollout; it also includes two design partners already live on the platform. Fluton, described as a confidentiality engine, provides privacy-by-default transactions across multi-chain ecosystems, using encrypted intents to combat phenomena like MEV (Maximal Extractable Value) attacks. AlphaEngine offers a platform where strategists can compete using encrypted methods, keeping their proprietary trading strategies private while attracting user liquidity.
Looking ahead, Fhenix has ambitious plans. The company expects to launch three more applications on CoFHE in the fourth quarter of 2026. Moreover, it anticipates announcing two strategic partnerships with major institutions in the coming weeks.
Guy Zyskind, the founder, has also confirmed ongoing work on a confidential stablecoin in collaboration with Tandem, the venture arm of Offchain Labs, a key investor in Fhenix and developer of Arbitrum.
The firm has garnered substantial financial backing, raising over $22 million in total funding. This includes a $7 million seed round in 2023 led by Multicoin Capital and Collider Ventures, followed by a $15 million Series A round in 2024 with Hack VC at the helm and participation from firms like Amber Group and Primitive.
Furthermore, strategic investments from Offchain Labs’ Tandem and Japan’s BIPROGY, a major IT service provider, signal growing institutional confidence in Fhenix’s vision, particularly for privacy-focused stablecoins and Web3 fintech in the Japanese market. As Ethereum staking continues to evolve, privacy-enhancing solutions like Fhenix become increasingly relevant for institutional adoption.
Navigating the complexities of on-chain privacy
While Fhenix champions a new frontier in on-chain privacy, the broader landscape of confidential computing isn’t without its complexities. A notable incident in late May 2026 saw a U.S. federal court order force Circle to freeze approximately $12.6 million in a confidential USDC contract operated by Zama, another FHE developer.
This action, stemming from a civil dispute unrelated to Zama, temporarily locked funds of users unconnected to the case.
The court order was reversed after three days, but the event highlighted the tension between privacy-preserving blockchain infrastructure and the centralized control often exerted over stablecoins by their issuers. It underscored that while FHE can encrypt balances and amounts, centralized assets remain susceptible to regulatory and legal actions.
However, Zama’s protocol design, which preserves visible sender and recipient addresses while encrypting balances, reportedly contributed to the swift reversal of the freeze.
For Fhenix, an important validation came from Consensys Diligence, which audited its system prior to launch. This endorsement from a reputable blockchain security firm provides a crucial layer of assurance for the integrity of the CoFHE system.
The launch initiates with a permissioned rollout, requiring contracts to be approved before using CoFHE in production, indicating a cautious approach to scalability and security. Such rigorous approaches help bolster the Ethereum network’s security as it integrates more advanced features.
Despite the significant strides, the company has clarified certain points regarding its token. As of October 20, 2026, Fhenix has not confirmed any official FEH token launch, tokenomics structure, or a guaranteed airdrop. While infrastructure development is underway, token issuance remains a separate and unconfirmed activity, advising caution against speculative claims.
Protecting user data is also a key challenge in Ethereum passkey cryptography, aligning with Fhenix’s goals.