Fhenix announced that its CoFHE coprocessor is now running in production on Ethereum and Arbitrum. Smart contracts on both networks can now operate on encrypted balances and positions, according to the project.
What Fhenix shipped
CoFHE went live on the Ethereum and Arbitrum mainnets on October 21, 2026, Fhenix said. The name stands for FHE coprocessor, with FHE referring to fully homomorphic encryption.
Developers can access the coprocessor with a single line of Solidity import, according to Fhenix. The project noted that privacy tooling has historically required developers to learn new languages, new chains, or both.
The coprocessor performs its heavy computation off-chain and then sends encrypted results back to the host EVM chain. Contracts using CoFHE can still interact with existing infrastructure on the host chains, rather than operating in a separate privacy environment.
Dual-mode tokens and launch lineup
Alongside the coprocessor, Fhenix introduced a Dual-Mode Token Standard. It allows users to move between public and private token balances in a single transaction, without bridges or wrapping.
Five retail-focused decentralized applications are launching with the mainnet, selected from a pool of around 60 candidates, Fhenix said.
The mainnet starts out permissioned, meaning contracts must be approved for an allowlist before they can use CoFHE in production. Testnets remain fully open to developers and users.
Performance claims
Fhenix points to benchmarks from its ACM CCS 2025 research. Its new threshold decryption method reportedly delivers approximately 20,000 times higher throughput than traditional approaches, along with up to 37 times lower latency.
Threshold decryption splits the power to decrypt among multiple parties, so no single party holds the full key.
From rollup to coprocessor
CoFHE is not where Fhenix started. The project originally pursued an FHE rollup architecture, then pivoted to the modular coprocessor model in pursuit of broader interoperability.
Fhenix acquired the Sunscreen team in July 2026, a group known for its FHE expertise. On the funding side, Fhenix raised a total of $22 million across seed and Series A rounds in 2023.
