Vishnu Asutosh Dasu
vdasu at psu dot edu

I am a PhD student in computer science (PhD CSE) at the Pennsylvania State University. I am advised by Prof. Gang Tan and work on developing secure and trustworthy software and machine learning systems. Currently, I am working on trustworthy code generation LLMs and fairness of LLMs. For my master's thesis, I worked on mitigating unfairness issues in trained neural networks. I also enjoy collaborating with Prof. Shagufta Mehnaz on privacy of LLMs and security of multimodal LLMs. In general, I am interested in topics in the intersection security, privacy, and machine learning. In another life, I worked on hardware security and cryptography.

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My Erdős number is 4: Paul Erdős → Israel Koren → Francesco Regazzoni → Takanori Isobe → Vishnu Asutosh Dasu

I would love to collaborate with like-minded researchers and am open to opportunities. Please reach out to me if you're interested!

profile photo
News
  • August 2024: Joined the CSE PhD program at Penn State!
  • July 2024: Our paper Privacy-Preserving Data Deduplication for Enhancing Federated Learning of Language Models is out on arXiv!
  • July 2024: Our paper NeuFair: Neural Network Fairness Repair with Dropout has been accepted at ACM ISSTA 2024!
  • March 2024: Passed my Master's defense!!
  • January 2024: Employed by Penn State as the Head Graduate Teaching Assistant for CMPSC 465: Data Structures and Algorithms, Spring 2024.
  • December 2023: Submitted my thesis research on mitigating unfairness in deep learning to ACM ISSTA 2024!
  • October 2023: Our paper FLTrojan: Privacy Leakage Attacks against Federated Language Models Through Selective Weight Tampering is out on arXiv!
  • October 2023: Our paper EvoquerBot: A multimedia chatbot leveraging synthetic data for cross-domain assistance has been published at Alexa Prize TaskBot Challenge 2 Proceedings!
  • August 2023: Joined the OpenMined Research Team as a Researcher!
  • August 2023: Employed by Penn State as the Head Graduate Teaching Assistant for CMPSC 465: Data Structures and Algorithms, Fall 2023.
  • June 2023: Graduated from OpenMined's Padawan Program!
  • May 2023: Started working with Prof. Gary Tan and Prof. Saeid Tizpaz-Niari as a Summer Research Assistant! Working on mitigating unfairness in deep learning models.
  • May 2023: Got a GPA of 3.9 this semester! Courses: CSE 587: Deep Learning for NLP (A), CSE 597: Security and Privacy of ML (A), DS 560: Causal Inference (A-), CSE 590: Colloquium (A)
  • April 2023: Our paper New Results on Machine Learning-Based Distinguishers has been accepted at IEEE Access!
  • April 2023: Selected to join OpenMined's Padawan Program!
  • February 2023: Started working with Prof. Shagufta Mehnaz on developing attacks to extract private data from federated language models!
  • February 2023: Started working with Prof. Rui Zhang on developing language models for our team EvoquerBOT in the Alexa Prize TaskBot Challenge 2!
  • December 2022: Got a perfect 4.0 GPA this semester! Off to a good start! Courses: IST 597: Adversarial Machine Learning, CSE 543: Computer Security, CSE 511: Operating Systems Design
  • November 2022: Selected to attend the Winter School on Responsible AI in The Dead Sea, Israel with a scholarship!
  • September 2022: Our paper PROV-FL: Privacy-preserving Round Optimal Verifiable Federated Learning has been accepted at the 15th ACM AISec Workshop co-located with ACM CCS 2022!
  • August 2022: Employed by Penn State as a Graduate Teaching Assistant for CMPSC 465: Data Structures and Algorithms, Fall 2022.
  • August 2022: Joined the MS CSE program at Penn State University Park!
Publications (Selected)

(* represents equal contribution)

Privacy-Preserving Data Deduplication for Enhancing Federated Learning of Language Models
Aydin Abadi*, Vishnu Asutosh Dasu*, Sumanta Sarkar*
Conditionally Accepted at Network and Distributed System Security (NDSS) Symposium, 2025

We develop a novel variant of the Private Set Intersection (PSI) protocol that securely removes all pairwise duplicates among datasets held by two more users in federated learning. Our protocl preserves user privacy and does not reveal any information about the datasets to the users and server. The deduplication protocol results in significant improvement to LLM perplexity and reduces GPU training time.

NeuFair: Neural Network Fairness Repair with Dropout
Vishnu Asutosh Dasu, Ashish Kumar, Saeid Tizpaz-Niari, Gang Tan
The 33rd ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA), 2023 (Acceptance Rate: 20.6%)

We develop randomized algorithms to mitigate unfairness in deep learning by dropping a subset of neurons from a trained neural network during at inference time. Our results show that a subset of neurons disparately contributes to unfairness and dropping them out during inference can improve fairness by up to 69%.

FLTrojan: Privacy Leakage Attacks against Federated Language Models Through Selective Weight Tampering
Md Rafi ur Rashid, Vishnu Asutosh Dasu, Kang Gu, Najrin Sultana, Shagufta Mehnaz
arXiv

We introduce two novel privacy leakage attacks against federated language models. First, we show that intermediate model snapshots can leak more sensitive data than the final trained model. Second, we show that tampering with a model's selective weights responsible for memorizing sensitive data can aggravate privacy leakage. Our best-performing method outperforms existing attacks with stronger adversary assumptions.

EvoquerBot: A multimedia chatbot leveraging synthetic data for cross-domain assistance
Team EvoquerBOT, Penn State University
Alexa Prize TaskBot Challenge 2 Proceedings, 2023

EvoquerBot is a multimedia chatbot developed for the TaskBot challenge, aimed at assisting users with cooking and DIY tasks in a single session. The bot addresses challenges like short development time, data quality, multimedia responses, and tailored conversation flow using agile classifier development, data augmentation, multimedia response design, and domain-specific dialogue state machines, ultimately improving user experience through superior task recommendations.

New Results on Machine Learning-Based Distinguishers
Anubhab Baksi, Jakub Breier, Vishnu Asutosh Dasu, Xiaolu Hou, Hyunji Kim, Hwajeong Seo
IEEE Access, 2023 (Acceptance Rate: 27.0%)
ePrint

We show new machine learning differential distinguishers for unkeyed and round-reduced versions of SPECK-32, SPECK-128, ASCON, SIMECK-32, SIMECK-64, and SKINNY-128. Our comprehensive experiments utilize neural networks and support vector machines in various settings and numerous input difference tuples.

PROV-FL: Privacy-preserving Round Optimal Verifiable Federated Learning
Vishnu Asutosh Dasu, Sumanta Sarkar, Kalikinkar Mandal
ACM Workshop on Artificial Intelligence and Security (AISec), ACM CCS 2022 (Acceptance Rate: 35.0%)

We propose PROV-FL, a secure and private federated learning protocol. PROV-FL utilizes homomorphic encryption and differential privacy to provide strong privacy guarantees. It is resilient to user dropouts/joins, supports verifiable aggregation, and requires only a single round of communication without a full-trusted third party.

Side Channel Attack On Stream Ciphers: A Three-Step Approach To State/Key Recovery
Satyam Kumar, Vishnu Asutosh Dasu, Anubhab Baksi, Santanu Sarkar, Dirmanto Jap, Jakub Breier, Shivam Bhasin
IACR Transactions on Cryptographic Hardware and Embedded Systems (CHES), 2022 (Acceptance Rate: 18.6%)
code (Artifact Evaluated)

We propose an end-to-end solution to perform SCA on stream ciphers by combining automated tools such as ML, MILP, and SMT. We demonstrate its efficacy by taking electromagnetic traces from a 32-bit software platform and performing SCA on the TRIVIUM stream cipher.

Three Input Exclusive-OR Gate Support for Boyar-Peralta's Algorithm
Anubhab Baksi, Vishnu Asutosh Dasu, Banashri Karmakar, Anupam Chattopadhyay, Takanori Isobe
INDOCRYPT, 2021
talk / ePrint / code

We develop a method to extend the Boyar-Peralta's algorithm to use XOR3 gates, add XOR3 gates to existing XOR2 implementations, and show several SOTA results on the linear layers of block ciphers using different logic libraries.

Further Insights On Implementation Of The Linear Layer
Anubhab Baksi, Banashri Karmakar, Vishnu Asutosh Dasu, Dhiman Saha, Anupam Chattopadhyay
Security and Implementation of Lightweight Cryptography Workshop (SILC), EUROCRYPT 2021

We provide new insights for different notions of XOR count, develop methods to find sequential XOR count implementations using SMT and MILP, and present new results using XOR3 gates on the AES MixColumn matrix.

LIGHTER-R: Optimized Reversible Circuit Implementation For SBoxes
Vishnu Asutosh Dasu, Anubhab Baksi, Sumanta Sarkar, Anupam Chattopadhyay
IEEE International System-on-Chip Conference (SOCC), 2019
code

We develop a framework that extends LIGHTER to add support for generating optimized implementations of 4x4 SBoxes using reversible logic libraries.

[Re] GANSpace: Discovering Interpretable GAN Controls
Vishnu Asutosh Dasu, Midhush Manohar T.K.
ReScience C, Volume 8, Issue 2, 2022
project page / code (Artifact Evaluated) / openreview / colab / blog

We reproduce the results and validate the claims presented in GANSpace: Discovering Interpretable GAN Controls.

Awards
  1. TCS Citation Award (3-time Recipient): Received the TCS Citation Award and appreciation from the Chief Technical Officer and Head of TCS Research thrice for performance and outstanding contribution to the organization.
  2. Scholarship: Received a scholarship to attend the Winter School on Responsible AI in The Dead Sea, Israel.
  3. Best Project Award: Received the Best Project Award among 13 teams during the Fifth Summer School on Computer Vision, Graphics and Image Processing, Indian Statistical Institute (ISI) Kolkata.
  4. IGVC: Placed 2nd in the Interoperability Profiles Challenge and 9th overall at Intelligent Ground Vehicle Competition (IGVC) 2018 among 26 teams. Second-best among all teams from India.
  5. ACM ICPC Regionals: Represented Manipal Institute of Technology, Manipal at the 2017 ACM ICPC Asia Regional Contest.
  6. DAGsHub Award: Received a $500 award from DAGsHub for successfully reproducing GANSpace: Discovering Interpretable GAN Controls and completing the ML Reproducibility Challenge Spring 2021.
Service
Talks
  • Secure Code Generation using LLMs at Penn State Security Reading Group (slides)
Technical Reports
"Where's Waldo?"
Ritwik Sarkar and Vishnu Asutosh Dasu
Presented at the Fifth Summer School on Computer Vision, Graphics, and Image Processing, Indian Statistical Institute (ISI), Kolkata, 2018
slides
Recipient of the Best Project Award

We develop a technique to determine the 3D coordinates of a human from a live video feed using a camera with a single lens (monocamera setup).

Hobbies

I enjoy powerlifitng, playing the guitar, and reading about history, theology, and philosophy.