Theodosian: A Deep Dive into Memory-Hierarchy-Centric FHE Acceleration

Theodosian is primarily an academic artifact (associated with an arXiv paper) rather than a production-ready software project. With 0 stars and 6 forks, its value lies in its research insights—specifically identifying the L2 cache as the primary bottleneck for CKKS kernels—rather than its market presence. In the competitive landscape of FHE acceleration, it faces significant pressure from established libraries like OpenFHE, Zama's Concrete, and Microsoft SEAL, all of which are moving toward GPU acceleration. The defensibility is low because the optimizations described (memory hierarchy tuning) are classic GPU engineering patterns that can be readily absorbed into more mature libraries. Platform risk is high because NVIDIA is increasingly optimizing its own libraries (e.g., cuFHE) and hardware for the large-integer modular arithmetic required by FHE. While the technical depth is high, the project lacks the network effects or integration surface (it's a reference implementation, not a pip-installable library) to survive as a standalone entity once major labs or NVIDIA standardize FHE primitives.