Funding
Funded
Hardware assisted homomorphic encryption (HE) acceleration.
School of Electronics, Electrical Engineering and Computer Science | PHD
Applications are now CLOSED
Reference Number
EEECS/2025/AK1
Application Deadline
28 February 2025
Start Date
1 October 2025
Overview
Homomorphic encryption is a transformative technology that enables computation on encrypted data1. This quantum-secure cryptography technique offers privacy-preserving operations on ciphertext with potential use in a variety of applications, ranging from healthcare to finance. Despite its advantages, HE often suffers from high computational cost, hindering its widespread adoption. A practical alternative to fully homomorphic encryption (FHE), is the somewhat homomorphic encryption (or SHE) schemes allowing a limited number of operations on encrypted data. These schemes are more efficient, and hold promise for real-world use cases. Some noticeable schemes include the CKKS, BGV and BFV, mostly named after their research team’s initials. Since SHE can still be computationally intensive with massive memory requirements, exploring hardware acceleration platforms like FPGAs and ASICs can improve performance for specific applications. With faster processing, HE and SHE become viable for tasks that were previously too slow, opening doors for new and much relevant use cases today including real-time data analysis on encrypted medical records, privacy-preserving machine learning, secure outsourcing of computations etc. Consequently, several technology companies including Intel, AWS, Microsoft, IBM, Samsung etc. are actively researching on this topic.
This project will explore algorithmic and architectural optimizations by designing and developing a specially optimized hardware accelerator for these somewhat homomorphic encryption schemes on FPGA. In the HE setting, there are two entities, client and cloud. The client encodes and encrypts its data and sends it to the cloud where homomorphic computations are performed on the encrypted data while keeping it confidential. As the processed data is sent back to client, it reads the processed data from the cloud in the encrypted format, and then decrypts and decodes it. While there is more work done today on accelerating cloud-side operations on high-end FPGA and ASIC platforms, very few earlier works focuses on the client side which is critical and challenging since the client side may use low end devices with stringent resource and performance constraints. The CKKS scheme (2) has emerged as a promising HE scheme as it allows computations on real numbers and consequently can cater wider range of applications. This research will explore various microarchitecture for the computationally intensive components in HE for acceleration via pipelining, parallelism, and memory access patterns. A benchmarking in terms of performance, power consumption, and cost will help understand the trade-offs in the design. OpenFHE will serve as a software baseline (3). Security enhancement of the hardware design against the side channel attacks will also be identified and addressed.
This work is best suited for someone who is familiar with a typical hardware design cycle including any HDL and FPGA design/verification tools. A foundation of cryptography will be useful.
References:
(1) Gentry, Craig. "Fully homomorphic encryption using ideal lattices." Proceedings of the forty-first annual ACM symposium on Theory of computing. 2009.
(2) J. H. Cheon, A. Kim, M. Kim, and Y. Song, “Homomorphic encryption for arithmetic of approximate numbers,” in Advances in Cryptology – ASIACRYPT 2017, T. Takagi and T. Peyrin, Eds. Cham: Springer International Publishing, 2017, pp. 409–437.
(3) OpenFHE: https://www.openfhe.org/
Funding Information
To be eligible for consideration for a Home DfE or EPSRC Studentship (covering tuition fees and maintenance stipend of approx. £19,237 per annum), a candidate must satisfy all the eligibility criteria based on nationality, residency and academic qualifications.
To be classed as a Home student, candidates must meet the following criteria and the associated residency requirements:
• Be a UK National,
or • Have settled status,
or • Have pre-settled status,
or • Have indefinite leave to remain or enter the UK.
Candidates from ROI may also qualify for Home student funding.
Previous PhD study MAY make you ineligible to be considered for funding.
Please note that other terms and conditions also apply.
Please note that any available PhD studentships will be allocated on a competitive basis across a number of projects currently being advertised by the School.
A small number of international awards will be available for allocation across the School. An international award is not guaranteed to be available for this project, and competition across the School for these awards will be highly competitive.
Academic Requirements:
The minimum academic requirement for admission is normally an Upper Second Class Honours degree from a UK or ROI Higher Education provider in a relevant discipline, or an equivalent qualification acceptable to the University.
Project Summary
Supervisor
Dr Ayesha Khalid
Mode of Study
Full-time: 3 or 3.5 years
Funding Body
Funding TBC