Subhrajit Das

Subhrajit Das

PhD Scholar

Computer Science & Engineering

IIT Gandhinagar, Gujarat

India

About me

I am a Director’s PhD Fellow in the Department of Computer Science and Engineering at the Indian Institute of Technology Gandhinagar, where I work with Prof. Abhishek Bichhawat and Prof. Yuvraj Patel. I am a member of the FUSS group and my current research explores harnessing the parallelism of modern CPUs in various workloads. My broader research interest includes CPU parallelism, distributed systems, and usable privacy & security.

Beyond research, I enjoy teaching and have served as a TA for several courses, along with guest lectures and a short course at the institute.

Education

Ph.D. in Computer Science and Engineering

Indian Institute of Technology Gandhinagar, India 2025 - Present

Master of Technology in Computer Science and Engineering

Indian Institute of Technology Gandhinagar, India 2023 - 2025

Master of Science in Computer Science

University of Kalyani, India 2021 - 2023

Bachelor of Science (Honours) in Computer Science

Panihati Mahavidyalaya (West Bengal State University), India 2018 - 2021

Projects

WimpyGPU: Leveraging Commodity Hardware for Compute-intensive GPU Tasks

Team Contributor at IIT Gandhinagar & University of Edinburgh (Oct 2025 - Present)

  • Investigating how clusters of commodity hardware can tackle compute-intensive tasks typically reserved for accelerators.

Developer Experience of Consent Management Platform Integration

Team Contributor at IIT Gandhinagar (Oct 2025 - Present)

  • Investigating the usability challenges developers face when integrating Consent Management Platforms (CMPs) into web applications.

Accelerating Large Integer Arithmetic with Parallel Addition, Subtraction, and Vedic-Based Multiplication Using AVX512

M.Tech. Thesis Work

  • Advisor: Prof. Abhishek Bichhawat, Co-advisor: Prof. Yuvraj Patel (The University of Edinburgh)
  • Designed high-performance faster data-parallel algorithms for large integer addition and subtraction using AVX512 for most cases.
  • Achieved average execution-time speedup of 2.06x for addition and 2.32x for subtraction (up to 131k bits) compared to the GNU Multiple-Precision Arithmetic Library (GMP).
  • Designed a faster Vedic-based multiplication algorithm for large integers using AVX512-IFMA for 256-bit operands, with execution-time speedup of 1.83x compared to the GMP library.
  • Additionally, designed approximate variants of the proposed algorithms for large integer addition and multiplication, achieving average execution-time speedup of 2.52x and 2.80x, respectively, compared to GMP.

Studies on Various Maximal Covering Location Problems using Genetic and Artificial Bee Colony Algorithms

M.Sc. Thesis Work

  • Advisor: Prof. Priya Ranjan Sinha Mahapatra, Co-advisor: Dr. Soumen Atta
  • Designed and implemented an algorithm for solving maximal covering location problems using genetic and artificial bee colony algorithms.
  • Achieved optimal benchmark results with CPLEX in 50% of cases, reducing the average computational time to 85.83 seconds, compared to over 1000 seconds for previous models, with an average gap of just 0.01%.

Reversible Multiplier Accumulate Unit (B.Sc. Project)

B.Sc. Project Work

  • Designed a multiplier accumulate unit using reversible gates for low power consumption and heat dissipation.

Instant Payment Gateway (IPG)

Team Contributor

  • Engineered an instant payment system using Parallel and Distributed Systems concepts.
  • Facilitated seamless and secure interoperability between parties, similar to UPI.
  • Implemented efficient transaction processing with load balancing, fault tolerance, and concurrency control to ensure high availability and scalability.

TennisServe: A Parallel Game Matching Server with OpenMP & MPI

Individual Contributor

  • Developed a simulation of a tennis game matching server where multiple players send requests for games: singles, doubles, male, female, or mixed.
  • Utilized OpenMP threads to handle client requests and MPI calls for player communication.
  • Managed the availability of limited tennis courts (4 courts) to continuously match players’ requests.
  • Completed as part of the Parallel and Distributed Course at IIT Gandhinagar.

Teaching Experience

Teaching Assistant

Indian Institute of Technology Gandhinagar, India Jul 2023 - Present
  • Assisted for the courses such as Distributed Systems and Cloud Computing, Computer & Network Security, Compilers, and Data Structures and Algorithms - I.

Guest Lectures on SIMD and Code Profiling

Indian Institute of Technology Gandhinagar, India Oct 2025
  • Given a couple of guest lectures on exploiting x86-64 data parallelism using compiler auto-vectorization, intrinsics and also profiling code using Linux perf and relevant syscalls for the course CS 612 - Computer Systems.

Guest Lecture on RAID

Indian Institute of Technology Gandhinagar, India Apr 2025
  • Given a guest lecture on RAID for the course Operating Systems (CS 330).

Principal Instructor

Indian Institute of Technology Gandhinagar, India Nov 2024
  • Served as the Principal Instructor for a Short Course titled “Code Profiling and Optimization” during Semester-I, 2024-25.
  • Topics covered: compiler flags (GCC/ICX), debugging (GDB), performance tools (timespec, rusage, rdtsc), profiling tools (perf, valgrind), and optimization strategies (caching, memory, vectorization, parallelization).

Publications

DigitsOnTurbo: Leveraging SIMD for Accelerating Large-number Arithmetic

Subhrajit Das, Abhishek Bichhawat and Yuvraj Patel

Under Review, 21st European Conference on Computer Systems (EuroSys 2026) Edinburgh, Scotland, UK
Online Authentication Habits of Indian Users

Pratyush Choudhary, Subhrajit Das, Mukul Paras Potta, Prasuj Das, and Abhishek Bichhawat

1st International Conference on Building a Secure and Empowered Cyberspace (BuildSec) New Delhi, India • Dec, 2024
View Publication

Updates

October 2025

Attended the Computer Systems Workshop at IISc Bangalore and presented a poster on our work on 'DigitsOnTurbo: Leveraging SIMD for Accelerating Large-number Arithmetic'

July 2025

Assisted in organizing web security CTFs for ICAN Faculty Development Program on Cybersecurity at IIT Madras

January 2025

Selected for the Director's PhD Fellowship at the IIT Gandhinagar

December 2024

Attended BuildSEC'24 in New Delhi and presented our work on 'Online Authentication Habits of Indian Users'. We also won the Best Paper Award there.