Flexible and Cost-Effective Chiplet-Based Accelerator for Fully Homomorphic Encryption

핵심 개념

CiFHER, a chiplet-based FHE accelerator with a resizable structure, tackles the high computational overhead of FHE through a cost-effective multi-chip module (MCM) design, achieving comparable performance to state-of-the-art monolithic ASIC accelerators while significantly reducing power consumption and manufacturing cost.

초록

The paper proposes CiFHER, a flexible and cost-effective MCM architecture for accelerating fully homomorphic encryption (FHE). FHE is an attractive solution for providing strong privacy guarantees, but its high computational overhead poses a challenge to practical adoption.

The key contributions of this work are:

1. Design of a flexible chiplet core with a composable number-theoretic transform (NTT) unit, allowing the distribution of memory and compute resources across multiple dies while leveraging the efficiency of vector NTT.

2. Introduction of generalized data mapping methodologies on a tiled FHE accelerator to resolve the network-on-package (NoP) communication bottleneck of MCMs.

3. Proposal of a limb duplication algorithm, an optimization tailored to the MCM design, reducing the amount of die-to-die communication and associated latency and energy overhead.

The paper explores various configurations of CiFHER, ranging from four 47.08mm^2 core dies to sixty-four 4.28mm^2 core dies, and demonstrates that a CiFHER package can achieve comparable performance to state-of-the-art monolithic ASIC accelerators while significantly reducing power consumption and manufacturing cost.

통계

The paper states that FHE workloads run over 10,000× slower than their unencrypted counterparts.
The monolithic ASIC FHE accelerator proposals, such as ARK, utilize massive chip areas of 373.6–472.3mm^2 to achieve considerable performance enhancements.

인용구

"CiFHER, a flexible and cost-effective MCM architecture for FHE acceleration."
"We design a flexible chiplet core with a composable NTT unit, which allows the distribution of memory and compute resources across multiple dies while taking advantage of the vector NTT unit."
"We introduce generalized data mapping methodologies on a tiled FHE accelerator to resolve the NoP communication bottleneck of MCMs."
"We propose limb duplication, an algorithmic optimization tailored to the MCM design, reducing the amount of die-to-die communication, which would have caused significant latency and energy overhead."

핵심 통찰 요약

CiFHER

by Sangpyo Kim,... 게시일 arxiv.org 04-02-2024

https://arxiv.org/pdf/2308.04890.pdf

더 깊은 질문

How can the composable NTT unit design in CiFHER be further optimized to improve performance and energy efficiency?

The composable NTT unit design in CiFHER can be optimized in several ways to enhance performance and energy efficiency. One approach is to explore different configurations of submodules within the NTT unit to find the most efficient combination for varying computational demands. By adjusting the number of submodules and their organization, the NTT unit can be tailored to specific workloads, maximizing computational throughput while minimizing energy consumption. Additionally, optimizing the data movement within the NTT unit, such as improving data shuffling and buffering techniques, can reduce latency and enhance overall efficiency. Furthermore, exploring advanced FFT algorithms or hardware optimizations for the NTT computation can further boost performance and energy efficiency of the NTT unit in CiFHER.

How can the potential challenges and trade-offs in scaling the CiFHER architecture to an even larger number of chiplets be addressed?

Scaling the CiFHER architecture to accommodate a larger number of chiplets presents several challenges and trade-offs that need to be addressed. One major challenge is the increased complexity of the network on package (NoP) communication as the number of chiplets grows, leading to potential bottlenecks and latency issues. To mitigate this, advanced routing algorithms and network topologies can be explored to optimize data movement and reduce communication overhead. Additionally, efficient data mapping strategies, such as block clustering with limb duplication, can help distribute data effectively among a larger number of chiplets, reducing fragmentation and improving overall performance.
Trade-offs in scaling CiFHER to more chiplets include increased power consumption, higher manufacturing costs, and potential challenges in maintaining coherence and synchronization among a larger number of cores. To address these trade-offs, careful power management techniques, cost-effective manufacturing strategies, and robust synchronization mechanisms need to be implemented. Furthermore, optimizing the design for scalability and modularity can facilitate the seamless integration of additional chiplets while maintaining performance and energy efficiency.

How can the data mapping and communication strategies in CiFHER be extended to support other types of homomorphic encryption schemes or cryptographic primitives?

The data mapping and communication strategies in CiFHER can be extended to support other types of homomorphic encryption schemes or cryptographic primitives by adapting the existing methodologies to the specific requirements of the new schemes. For different encryption schemes with distinct data access patterns, the data mapping algorithms can be customized to optimize data distribution and communication among cores. By analyzing the unique characteristics of the new encryption schemes, tailored data mapping strategies can be developed to ensure efficient data movement and processing.
Furthermore, the communication strategies in CiFHER can be enhanced to support a broader range of cryptographic primitives by incorporating flexible routing algorithms, adaptive network configurations, and efficient data exchange mechanisms. By designing a modular and adaptable communication framework, CiFHER can be extended to seamlessly integrate and support various cryptographic primitives, enabling versatile and efficient processing of different types of encrypted data. Additionally, exploring novel data mapping and communication techniques that are agnostic to specific encryption schemes can enhance the versatility and scalability of CiFHER for accommodating a diverse set of cryptographic primitives.