Hermes: Efficient Global Homomorphic Aggregation over Mutable Packed Ciphertexts

Hermes addresses a critical bottleneck in the practical application of Fully Homomorphic Encryption (FHE): the trade-off between ciphertext packing (needed for efficiency) and mutability (needed for real-world databases). While FHE libraries like Microsoft SEAL or Zama's Concrete provide the primitives, the architectural 'structural mismatch' Hermes solves—enabling global aggregation over frequently updated packed ciphertexts—is a deep domain expertise moat. The project scores a 7 for defensibility because, while the code is currently a fresh research prototype (3 days old, 0 stars), the underlying cryptographic novelties are non-trivial to replicate without significant academic and engineering background. Frontier labs like OpenAI are unlikely to build this as it is infrastructure-level privacy tech, a space currently dominated by specialty firms (Zama, Enveil) and cloud providers (Azure Confidential Computing). The primary risk is not from LLM labs but from hardware acceleration (ASICs/FPGAs) or new FHE schemes that might eventually make software-level packing optimizations less critical. However, the 'data gravity' of encrypted database architectures usually leads to long-term stickiness.