Sunscreen

Sunscreen builds developer tooling for fully homomorphic encryption, letting engineers compute on encrypted data without decrypting it. The problem it targets is usability: writing directly against FHE libraries requires understanding scheme parameters and circuit structure, and the performance gap between an expert and a non-expert spans orders of magnitude, which leaves most teams stuck at demos.

At the core are the Parasol compiler and the SPF framework. A developer writes a function in C and marks which inputs and outputs must stay hidden, and the compiler picks TFHE parameters, generates the circuit and parallelises it. A control stack supplies what FHE needs to run in practice: off-chain ciphertext storage, access control, key management with a threshold committee answering decryption requests, and a service that executes the computation on the developer's behalf. A data bus acts as a pull oracle, watching the chain for computation, permission and decryption requests and writing results back. In July 2026 Sunscreen was acquired by Fhenix, with the team taking on research across TFHE, BFV, encrypted computation and post-quantum work while the code stays open under AGPL; before that, compiled programs could be deployed and run through Lattica's platform.