01 Research


My research sits where machine learning meets security: how adversarial inputs break vision models, and how to defend them cheaply enough to run on the edge — work I'm now extending towards LLM systems.

Bachelor's Thesis · 2025

LightDefend

A lightweight hybrid adversarial defense for real-time edge object detection

Object detectors deployed at the edge are exposed to adversarial inputs but cannot afford heavyweight defenses. LightDefend combines Gradient Masking with Runtime Feature Sanitization to restore detection confidence under attack while keeping latency overhead minimal — security that fits in a real-time budget.

PyTorchYOLOv8COCO 2017FGSM
Threat model
Fast Gradient Sign Method (FGSM) perturbations on input images
Model
YOLOv8 object detector
Data
COCO 2017, evaluated across 30 batches
Defense
Gradient Masking + Runtime Feature Sanitization
Result0.62 → 0.84
// How it works

Attack, then absorb.

Two lightweight defensive layers work around the detector, designed for minimal latency overhead — security that fits a real-time budget.

01
Input frame
Camera frame headed for a real-time detector.
02 · attack
FGSM attack
ε-bounded perturbation along the loss gradient sign.
03 · defense
Gradient Masking
Denies the attacker a clean gradient signal to follow.
04 · defense
Feature Sanitization
Cleans perturbed intermediate features at runtime, inside YOLOv8.
05
Detections
Confidence restored, latency budget intact.
// Interactive

What an attack looks like.

Drag the budget. The perturbation stays small; its effect on a detector does not.

x · clean
+
ε · sign(∇ₓJ)
=
x′ · adversarial

Interactive illustration of how FGSM builds an adversarial input — not live model output.

x′ = clip( x + ε · sign( ∇ₓ J(θ, x, y) ) )

One gradient step, pushed in the direction that hurts the model most. Changes that look like noise to a person can collapse a detector's confidence. LightDefend is built to absorb that push at inference time, cheaply enough for the edge.

// Research interests

Where I'm looking.

01

Adversarial Machine Learning

How small, deliberate perturbations break vision models — and how to make them recover.

02

Edge AI Security

Defenses light enough to run in real time on constrained hardware, not just in the lab.

03

LLM Systems

Building and securing language-model systems: evaluation, guardrails and deployment.

04

Secure DevOps

Security testing as part of the pipeline — VAPT, OWASP and threat modelling by default.

// Publications & writing

On record.

Papers and preprints will appear here as they're published.

2025
LightDefend: Hybrid Gradient Masking and Runtime Feature Sanitization for Edge Object Detection
Devansh Sati — B.Tech Thesis, BTKIT, Uttarakhand Technical University
Thesis
// Applied security

Research grounded in real attacks.

Before the thesis, industry work on the offensive and defensive side shaped how I think about threat models.

security
Honda Motorcycles India
VAPT automation · OWASP · Threat modelling · Secure CI/CD
security
Maruti Suzuki India
Breach Attack Simulation · Network monitoring
security
DevOps VAPT Automation
Vulnerability scans wired into CI/CD with automated reporting