Fully Homomorphic Encryption (FHE) allows for secure computation on encrypted data. Unfortunately, huge memory size, computational cost and bandwidth requirements limit its practicality. We present BASALISC, an architecture family of hardware accelerators that aims to substantially accelerate FHE computations in the cloud. BASALISC is the first to implement the BGV scheme with fully-packed bootstrapping -- the noise removal capability necessary for arbitrary-depth computation. It supports a customized version of bootstrapping that can be instantiated with hardware multipliers optimized for area and power. BASALISC is a three-abstraction-layer RISC architecture, designed for a 1 GHz ASIC implementation and underway toward 150mm2 die tape-out in a 12nm GF process. BASALISC's four-layer memory hierarchy includes a two-dimensional conflict-free inner memory layer that enables 32 Tb/s radix-256 NTT computations without pipeline stalls. Its conflict-resolution permutation hardware is generalized and re-used to compute BGV automorphisms without throughput penalty. BASALISC also has a custom multiply-accumulate unit to accelerate BGV key switching. The BASALISC toolchain comprises a custom compiler and a joint performance and correctness simulator. To evaluate BASALISC, we study its physical realizability, emulate and formally verify its core functional units, and we study its performance on a set of benchmarks. Simulation results show a speedup of more than 5,000 times over HElib -- a popular software FHE library.

翻译：全同态加密（FHE）允许对加密数据进行安全计算。然而，巨大的内存需求、计算开销和带宽要求限制了其实用性。我们提出BASALISC，一个旨在显著加速云端FHE计算的硬件加速器架构系列。BASALISC是首个实现BGV方案并支持全打包自举（即任意深度计算所必需的噪声消除能力）的架构。它采用定制化的自举版本，可通过针对面积和功耗优化的硬件乘法器实例化。BASALISC是一种三层抽象层次的RISC架构，面向1GHz ASIC实现设计，并正在推进基于12nm GF工艺的150mm²芯片流片。其四层内存层次结构包括一个二维无冲突内部内存层，可在无流水线停顿的情况下实现32 Tb/s的基-256 NTT计算。该冲突解决置换硬件经过泛化设计并被重用，以在计算BGV自同构时无吞吐量损失。BASALISC还配备专用乘累加单元以加速BGV密钥切换。其工具链包含定制编译器及联合性能与正确性仿真器。为评估BASALISC，我们研究了其物理可实现性，仿真并形式化验证了核心功能单元，并通过一组基准测试分析了其性能。仿真结果显示，相较于流行的软件FHE库HElib，加速比超过5000倍。