The migration of computation to the cloud has raised privacy concerns as sensitive data becomes vulnerable to attacks since they need to be decrypted for processing. Fully Homomorphic Encryption (FHE) mitigates this issue as it enables meaningful computations to be performed directly on encrypted data. Nevertheless, FHE is orders of magnitude slower than unencrypted computation, which hinders its practicality and adoption. Therefore, improving FHE performance is essential for its real world deployment. In this paper, we present a year-long effort to design, implement, fabricate, and post-silicon validate a hardware accelerator for Fully Homomorphic Encryption dubbed CoFHEE. With a design area of $12mm^2$, CoFHEE aims to improve performance of ciphertext multiplications, the most demanding arithmetic FHE operation, by accelerating several primitive operations on polynomials, such as polynomial additions and subtractions, Hadamard product, and Number Theoretic Transform. CoFHEE supports polynomial degrees of up to $n = 2^{14}$ with a maximum coefficient sizes of 128 bits, while it is capable of performing ciphertext multiplications entirely on chip for $n \leq 2^{13}$. CoFHEE is fabricated in 55nm CMOS technology and achieves 250 MHz with our custom-built low-power digital PLL design. In addition, our chip includes two communication interfaces to the host machine: UART and SPI. This manuscript presents all steps and design techniques in the ASIC development process, ranging from RTL design to fabrication and validation. We evaluate our chip with performance and power experiments and compare it against state-of-the-art software implementations and other ASIC designs. Developed RTL files are available in an open-source repository.
翻译:计算到云层的迁移引起了隐私问题, 因为敏感数据由于需要解密处理而容易受到攻击, 敏感数据很容易受到攻击。 完全单调加密( FHE) 缓解了这一问题, 因为它能够直接在加密数据上进行有意义的计算。 然而, FHE比未经加密的计算慢了数量级, 妨碍了其实用性和被采纳。 因此, 改善 FHE 性能对于其真正的世界部署至关重要。 在本文中, 我们展示了长达一年的努力, 设计、 实施、 结构化和后硅校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校: 校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校校